Chemical Engg Reviewer

A 6-blade turbine agitator with a diameter of 1.5ft is used to mix a solution with a viscosity of 10cP and a density of 95lb/ft 3. N=120rpm. Calculate the theo horsepower required if the tank is provided with 4baffles. 2hp. A double-flight helix impeller 3ft diameter and 3ft high is operating at 30rpm in a 3.2ft diameter tank. 85% full, 1000poise and 65lb/ft 3. Estimate hp requirement. 7hp A mixing tank set-up that follows curve 2 of Fig. 18-17 Perry, 8/ed. Is using vertical blades of H=3in. Width of each baffle. 6inches. A three-blade propeller is used to mix a fluid in the laminar region. Da=0.3m; N=1.5Hz. If flat two-bladed paddle D a=0.75m. What is N. 24rpm An agitation vessel is equipped with a turbine impeller having a diameter of 30cm. density=1000kg/m 3; viscosity=1x10-3  Pa-s;  N=100rpm. What is NRe. 150,000 An agitator with a diameter of 2ft and a speed of 100rpm is mixing rubber-latex compound with a viscosity of 1250 poise and a density of 70lb/ft3. The N Re for the mixing operation is 5.56  An industrial mixing tank uses a 1.5ft diameter impeller operating at a speed of 120rpm. If 1000rpm, D a is 6inches.. Decreasing the shape factor, S 1, the ratio of the impeller to the tank diameter Da/Dt, when the baffles are few and narrow will increase the  power requirement. Following the “standard” proportions in the design of a 6 -blade turbine agitator, if an impeller has a diameter of 20cm, what would be the recommended tank diameter and the depth of the liquid in the tank, in cm. 60cm, 60cm. For a pitched-blade turbine agitator, increasing the shape factor, S 2 defined as the clearance from the bottom of the tank, E/ D t, the power requirement will decrease. If the set-up given in prob. 18 is to mix a solution with a viscosity of 5 cP and a density of 65lb/ft 3, what will be the hp requirement if the speed of the impeller is 60rpm. 3.3hp. If the tank in Prob. 9 is unbaffled, what will be the power requirement. 0.42hp. If the viscosity of the liquid i s reduced by ½ due to heating of the liquid inside the tank, what will be the percentage reduction in the power requirement. 54%. In agitation, for N Re of 1000, the power requirement in a baffled tank is approx. 55% per 55% per cent higher/lower than in unbaffled tank. In the motion of the impeller blades against the liquid in the mixing tank, the force acting perpendicular to the surface of the impeller is referred to as drag force. In the use of turbines for low-viscosity liquids, rapid currents that destroys stagnant pockets occur. Near Near the impeller. It is desired to agitate a liquid having a viscosity of 1.5x10 -3Pa-s and a density of 969 kg/m 3 in a tank having a diameter of 0.91m. W= 0.0381. Calculate the required kW. 0.190kW  One effective method of preventing vortex formation in a mixing tank where the shaft of the impeller is vertical, is to install baffles. Referring to prob.18, what will be the power requirement if the speed is increased to 80rpm. 7.8 hp Referring to prob.18, what will be the power requirement if the speed i s reduced to 10rpm. 2.3hp Relatively, the shape of the mixing tank, say cylindrical compared to a square or rectangular tank, has practically no effect on the power requirement. True.

The dimensionless number that describes the effect of wave motion on the surface of a liquid especia lly in agitation and mixing is expressed in terms of Froude of Froude number. The velocity components induced by the rotation of the impeller in the mixing process tends to induce the formation of vortex and swirling. These velocity components are tangential and radial. Using the data given in prob.15 and referring to Fig.18-17 Perry 8/ed, determine the power requirement if the mixing system is described by curve. 5. 5 hp. What will be the recommended volume of the solution to be charged in the mixing tank given in prob.18. Neglect the volume occupied by the mixer and baffles. 170ft 3 When blending two or more flammable liquids in a tank, it is appropriate to use jet use jet mixers. When strong vertical currents in the mixing tank is desired, it is best to use propellers use propellers When the NRe in a mixing tank is less than 10, the flow is considered laminar. In this range, the property that becomes unimportant in determining the power requirement is density of fluid.

20% Oleum means that in 100lb, there are 20lb of SO3  and 80lb of  H 2SO4. 90% of the NH 3 entering an NH 3-oxidation unit is converted to HNH 3 and 10% loss of NH 3 is due to conversion losses, NO in the stack gases and miscellaneous losses. Kg of NH3 necessary to produce 60,000 kg of 62 wt% HNO 3 is 12,000. A 20% aqueous sol’n of Na2CO3 and 25% aqueous sol’n of Ca(OH)2 were reacted to produce caustic soda sol’n. Precipitate contains 5% H2O, 1% NaOH, 94% CaCO 3. The conc. Of NaOH sol’n p roduced is 10.97%. A cement clinker with the ff analysis: Cao=64%, SiO 2=21%, Fe2O3 and Al2O3. The MT of silica required for a 300-day operation per year is 20,000. A cement company uses 3000MT of gypsum a month. Portland cement, the MT clinker produced monthly by the cement plant is 75,000. A plant near Maria Cristina Falls is to manufacture NH 3  by using a stoichiometric mixture of N2 and H2. The moles of H 2 present in the mixture if 100mol of pure electrolytic H 2 is used is 84.95 moles. A water solution of molasses contains 10% by weight sucrose (C12H22O11). The weight percent of C 2H6O in the sol’n after 90% of the sucrose has been converted to C 2H6O by fermentation is 5.1%. An analysis of the gases entering the converter of an ammonia oxidation nitric acid plant indicates that the gases contain 0.066lb of NH 3  and 0.934lb of air per pound of gas. 1lb of the gas leaving the converter contains 0.00361lbmol of NO (no NO 2). % NH3  converted to NO is 93%. At a plant which produces H 2SO4 by the contact process, a large storage tank currently holds 100,000kg of 20% oleum, where 20% oleum means that in 100kg of material there is 20kg of SO3 dissolved i n 80kg of pure H2SO4. The weight percent H 2SO4  in the final mixture in the tank is 80.4%. Bauxite containing 61% Al 2O3 and 8% SiO 2 is roasted and dissolved in caustic soda to form a solution from which iron present is precipitated and filtered out. The cost of caustic soda needed to produce 1000kg of  pure Al2O3 assuming 10% more than the t heo amount of NaOH needed is used. P used. P 6065. Bio-degradable detergents can be readily oxidized. Builders are added to soap to boost cleaning power.

Catalyst used in hydrogenation of oil is  Nickel. Catalysts used in the manufacture of sulfuric acid by chamber and contact processes are respectively oxides of nitrogen and V 2O5 on a  porous carrier. Cement mainly contains Cao, SiO 2 , Al 2O3. Coefficient of thermal expansion of glass is decreased by the addition of  ZnO during its manufacture manufacture.. Contact process  yields acid of higher concentration than chamber  process. Cumene is the starting material for the production of phenol of phenol and and acetone Economics of “Solvay Process” depends upon the efficiency of ammonia recovery and size of plant. Enamels give Enamels give good glossy finish Essential oils are usually obtained using steam using  steam distillation. Fat splitting catalyst is ZnO. is ZnO. Free alkali in toilet soap is less than that in a laundry soap. Function of thinner in a paint is to  suspend pigments and dissolve film forming materials. Fusion of bauxite and Limestone and  Limestone produces  produces high alumina cement. Glauber’s salt is sodium is sodium sulfate decahydrate. Gypsum is calcium sulfate. Hydrazine is largely used as rocket fuel. In a liquid Cl 2 plant, chlorine gas with some H 2 gas is liquefied, with part of the Cl 2 made to form HCl, according to the ff diagram. The Cl 2 sent to synthesis plant in MT is 22.7. In contact process, SO 3, is absorbed in 97% H 2SO4  and not in water  because water forms an acid mist which is difficult to absorb. In the lime soda process for caustic soda manufacture, lime is made to react with water and then with soda ash. The metric tons of lime that will be needed t o produce 100MT of 25% liquid NaOH is 31.21 MT. In the Lurgi coal gasifier large quantity of coal can be processed. Metallic soap is aluminum or calcium salt of fatty acids. Oil is a mixture of glycerides of fatty acids. Oxygen is produced by fraction of air using both Linde’s and Claude’s  process. Permanent hardness of water is due to the presence of calcium and magnesium sulfates magnesium sulfates and chlorides. Plasticizers are added to paints to give to give elasticity and prevent cracking of the film Producer gas consists mainly of CO, CO 2 , N 2 , H 2. Rancidity of oil can be reduced by hydrogenation. Raw materials for “Solvay Process” for manufacture of the soda ash are  salt, limestone, ammonia, and coke oven gas. SO2 is bubbled through hot sugar-cane juice to act as an acidifying agent  Soap cannot be used with hard water because they form insoluble calcium soaps which precipitate. Solvent used for extraction of oil is methyl ethyl ketone. The catalyst used in the manufacture of DDT from chloral and chlorobenzene is oleum. The electrolytic reaction for the production of aluminum may be written as Al2O3 + 3/2 C  2Al + 3/2 CO 2, 235,000cal of energy (in the form of electricity) is consumed for the production of 2gmol of Al. Amount to be paid for elec. power per lb Al produced is  P 0.066/lb Al. The main use of HCl is in the drilling of petroleum wells and pickling of steel sheets. The MT of CaCO 3 needed to produce 100MT of soda ash daily by the Solvay process is 93.34. Trinitro-toluene is an explosive.

Unsaturated oils compared to saturated oils have lower melting point and higher reactivity to oxygen. Using the data given below, the metric tons of rock phosphate (CaFCa4(PO4)3) needed to produce 6000MT of 90% purity superphosphate is 9530. Varnish does not contain pigment. contain  pigment. Wax is a mixture of esters of polyhydric alcohols except glycerin. Which is the main reducing agent during the production of iron from iron ore in a blast furnace. CO Which of the ff is the common pollutant emitted from metallurgical smelters, thermal power plant and cement plants. SO2 Which of the following is a detergent. Alkyl detergent.  Alkyl benzene sulfonate. Which oil is preferred for paint manufacture. Drying manufacture.  Drying oil  Widely used method for conditioning of boiler feed water is hot-lime  soda process. Yellow glycerin is made into white, using activated carbon. Zeolite removes both temporary as well as permanent hardness of water  by precipitating calcium and magnesium present in water as insoluble zeolites. Sodium chloride.

A continuous re-circulating aerobic biochemical process that keeps cells in suspended growth activated sludge process. A global treaty that aims to diminish and eventually phase out CFCs.  Montreal protocol A global treaty that aims to protect human health and the environment from the persistent organic pollutants. Stockholm Convention A global treaty that aims to regulate emissions of greenhouse gases.  Kyoto Protocol  A neurological disease characterized by trembling, inability to walk and speak and even serious convulsions that can lead to death due to ingestion of mercury minimata. A phenomenon where a cold layer of air becomes trapped by a layer of warmer air above due to a lack of wind circulation or the presence of certain topographical features, such as mountains, resulting to air  pollution being trapped in the lower, cooler layers of the troposphere. Thermal inversion A stack in an urban area is emitting 80g/s of NO. It has a n effective stack height of 100m. Estimate the ground level conc. At 2km downwind on the centerline. 63.7 microgram/m 3 A trace metal which causes Itai-itai disease is cadmium. A wastewater with a BOD/COD = 1 indicates that biological treatment is most practical. A water sample was analyzed to contain 150mg-L -1CO3-2  and 100 -L 1 HCO3-2 at a pH of 8.00 at 25 OC. Total alkalinity in terms of CaCO3 is 332ppm. Aeration of water is done to remove dissolved gases. An electrochemical process used in the removal of colloidal matter in wastewater through reduction of electrostatic charges surrounding the solids is called coagulation. Biomes are distinguished or identified by its dominant plant life. Calculate the theo oxygen demand (ThOD) of 150ppm glucose. 160ppm Class of water intended for primary contact recreation such as bathing, swimming, skin diving, etc. Class B Component of CFC’s CFC ’s that causes destruction of 100,000 molecules of ozone. chlorine Denitrification is carried out when bacteria break down nitrates and release nitrogen gas. What are these bacteria. Anaerobic bacteria.  Anaerobic bacteria.

During which of the ff operating conditions of an automobile CO content in the exhaust gas is maximum idle running. Ecological Solid Waste Management Act of 2000 is otherwise known as RA as RA 9003 For a given temperature profiles, determine which profile is neutrally

stable.1 stable.1 From question no. 15, estimate the ground level conc. At 2km downwind, 0.1 km off the centerline. 60microgram/m3 Gas responsible for the rotten egg of waste water. Hydrogen  Hydrogen sulfide. Generic term used to describe the particulate matter carried in the effluent gases from furnaces burning fossil fuels  fly ash. Hardness of water is usually expressed as parts per million of CaCO3. If the three-day BOD (BOD 3 ) of a raw sewage is 55ppm (k=0.55/day), what is the ultimate BOD. 68ppm Insufficient washing of sand grains in a rapid sand filter causes mud balls. Involves the accumulation of trace metals through each species of the food chain. Biomagnification. chain. Biomagnification. It is a phenomenon that results in the overabundance in the algae growth in bodies of water. It is also the natural process of nutrient enrichment that occurs over time in a body of water. Eutrophication. water.  Eutrophication. It is a very unstable gas used for disinfection, a very powerful oxidant capable of oxidizing 200 to 300 times more than chlorine and can reduce complex taste, odor and color ozone. It is defined as the controlled decomposition of organic materials, such as leaves, grass, and food scraps. composting  It is defined as the role of the organisms in the community.  Niche. It is described as the c loud of air pollution trapped by thermal inversion.  smog  It is used a s bonding agents in building and furniture construction which may cause drowsiness, nausea and headaches when exposed to low level concentration. formaldehyde concentration. formaldehyde Legislation that presents the revised water usage and classification.  DENR AO no. 34. Maximum allowable concentration of CO 2  in air for safe working is 5000 ppm. 5000 ppm. Most aquatic organisms can survive in pH range of about 6 to 9. Most commonly used coagulating agent. Aluminum agent.  Aluminum sulfate.  Nitrates more than 50ppm in water leads to a disease called mathenoglobenemia. Organisms that belong to the second trophic level. Herbivores. level.  Herbivores. PAN is a powerful lachrymator or t ear producer formed from unburned hydrocarbons, aldehydes, nitrogen oxides and oxygen. PAN stands for  peroxyacetyl nitrate. Part of the atmosphere where most of the photochemical reactions take  place. Mesosphere.  place. Mesosphere. Particulates (< 1micrometer) remaining suspended in air indefinitely and transported by wind currents are called aerosols Problem Solving Process of converting nitrogen gas to ammonia is called nitrogen  fixation. Process where decomposers return back the nitrogen to the soils t hrough the remains and waste of plants and animals. Ammonification. animals.  Ammonification.

Process whereby coarse matter (suspended or floating) of a certain size can be strained out of flowing water with the aid of bars, fine wires or rocks. Screening. Recyclable material labeled as no. 3 PVC. 3  PVC. Removal of all settleable particles rendered settleable under the influence of gravity, basically the theory of gravity under the influence of which all particles heavier than water tend to settle down. Sedimentation. Temporary hardness is hardness  is a substance in water is removed by Lime Soda Process. The alkalinity of wastewater is due to the presence of the following except dissolved CO2. The amount of chlorine available in water a fter the disinfection is called residual chlorine. The liquid produced when water percolates through any permeable material. leachate The permissible color for domestic water supply in ppm is 20. The pH of a water sample was found to be 6.3. The bicarbonate was measured to be 2.1x10 -3 M. Calculate the total carbonate if pK a1 a1 and pk a2 a2 are 3.3 and 10.33, respectively. 2.8x10-3 The process of killing infective bacteria in water is called sterilization. called  sterilization. The process where more harmful substances are produced from less harmful ones. Synergism. The red brownish color of water is due to the presence of dissolved impurities of iron and manganese. The resistance of water to the passage of light through it is a measure of the turbidity. The total solids in water are due to the presence of  suspended and dissolved solids. These are accumulated solids removed from separation equipment such as settling tanks and clarifiers. sludge. clarifiers.  sludge. These are closed compartments that use gravitational force to extract dust and mist and typically used only for larger particles. Settling chamber  These organisms feed on the waste of the ecosystem. Detritivores. ecosystem.  Detritivores. These reddish brown oxides in concentrated form may produce an abnormal accumulation of fluids in the lungs. NO lungs. NO x This provides the blueprint for action t owards sustainable development  Agenda 21 Total uptake of chemicals by an organism from food items as well as via mass transport of dissolved chemicals. Bioaccumulation. chemicals.  Bioaccumulation. Type of recycling that involves recovery of chemicals or energy from  post-consumer waste materials. tertiary Type of wastewater treatment that employs biological methods to remove fine suspended, colloidal and diss olved organics by biochemical oxidation. Secondary treatment. Type of wastewater treatment that employs physical and chemical treatment methods to remove or reduce a high percentage of suspend solids and toxic materials. Primary materials. Primary treatment. Water treatment that destroys disease-causing bacteria, nuisance  bacteria, parasites and other organisms and remove soluble iron, manganese and hydrogen sulfide from water. Chlorination. What is the atmospheric condition when the lapse rate is >10 OC/km. Superadiabatic. When a sample of water is added to a medium of agar and incubated at 37OC for 24hours, colonies of bacteria formed are countered. This test is called Total Count Test. Which of the ff is NOT classified as heavy industry in the list of environmentally critical projects.. Forestry projects.. Forestry projects

Which of the following is NOT a physical characteristic of wastewater.  Hardness. Which of the following is not use for the disinfection of water. Sulfuric acid. Which of the following is not used as adsorbent material. Water. Which of the following maybe used to measure the assimilative capacit y of a stream. BOD. stream. BOD.

4 kg of water is placed in an enclosed volume of 1m3 heated until 150C. Mass vapor is 2.542 kg.

A heat pump provides 75MJ/hr to a house. Compressors require 4kW of energy. COP is 5.21

A steel cast ing 40kg at 450C is quenched in 150kg oil. Entropy is 9.8kJ/kg.

Air undergoes isentropic compression from 14.7 psia, 68F to 180.6psia and 621.5F. -94.8Btu/lbm An ice-making machine operates cyclica lly between 0-25C. The work done to freeze 100kg water at 0C to ice is 733.94kcal. An ideal Otto engine operating at the end of compression (840F) and expansion (2540F) with compression ratio of 7.5. Efficiency is 55.3% An Otto cycle compression ratio of 7.5 operates at 14.2psia and 85F. The  pressure and temperature at the end are 238psia, 759F.

Calculate the entropy of steam at 60psia with a quality 0.6. 1.16

The work polytropic compression pf air from 15psia, 1ft3 to 150 psia and 0.15 ft3 is 5150ft-lb. The work required to compress a gas reversibly according to pV 1.3 is 50000ft-lb. Change in internal energy is 48.2Btu The work required to compress a gas reversibly according to pV 1.3 is 50000ft-lb. Heat loss is -16.1 Btu There are removed 500Btu/min of heat from 440R to 550R. if COP is ¾ of Carnot, heat rejected is 667Btu/min.

From 80F and 6ft3, 10lb H2 changes to 150F and 10ft3. Entropy is 8.1Btu/R From above find volume of vapor 0.9985m3. From above, heat rejected is 13.3Btu. From above, work done is 27Btu. From above, work done is -719btu/lb air From above, work input is 3.95hp.

How many TOR required to produce 10MT of ice at -10C to 22C i f losses are 15% of the chilling and freezing load. 17TOR If 150 L of N2 gas expands adiabatically at 1 atm to final volume of 250 L. 0.49 atm In a Carnot cycle operating on N2, heat supplied is 40Btu and expansion ratio is 15.6 at 60F. Efficiency is 67%. In an isentropic compression, P1- 100 psia, P2- 200 psia, V1- 10in3 and y1.4. Find V2- 6.1in3

Steam engine is operating at 220-35C and delivers 8hp and efficiency of 30%. What is the actual efficiency. 11.3% Steam generated in a power plant at 8600kPa and 500C fed to a turbine. Exhaust at 10kPa is saturated liquid. The efficiency of Rankine cycle is 39.7%. Steam is expanded from 700F and 200psia to 5psia in an 87% efficient turbine. Final enthalpy is 1105.23 Btu/lbm

If 1lbm of steam at 14.7psia, 63% quality is heated isentropically, at what  pressure. 2585 psia

experiment that 1.000 gram of M combines with an excess oxygen to form 2.019 grams of oxide. The element M is manganese

27 13

4

 Al  2 He



mass Fe3O4 = 23g, In the reaction of Fe 3O4 with carbon to form carbon dioxide and iron, the number of moles of carbon required to convert Fe3O4 to product 0.2. mass fraction solute = 35 ppm . What is the concentration of chloride ion in percent in a solution that contains chloride 3.5 E-3%. mass mixture (Cu2O and CuO) = 1.000g mass Cu = 0.865. The mass of Cu2O in the original sample of the mixture must have been 0.742g. mass O2 = 10.0g . What is the theoretical yield of SO 2 for the reaction of the given mass O 2 with sufficient S for complete reaction. 20.0g.

30

 P    X 

15

9 1 4 Be 1 H  

___ 

2 1 H 

8

Be

% composition HC C = 84.2% H = 15.8% . What is its empirical formula C 4 H. 54.45% carbon 9.09% hydrogen, 36.36% oxygen . What is the empirical formula. C 2 H 4O. a 1-L vessel established equilibrium with the following reaction: 2SO 2 + O2 = 2SO3 mol SO2 = 0.11 mol O2 = 0.05 mol SO3 = 0.12 another 1-L vessel is used and contains SO 2 mass SO2 = 96g . How much O 2 (in grams) must  be added, if at equilibrium, one half of SO2 will be converted to SO 3 13.34.

a compound containing only phosphorus and hydrogen was fully combusted mass yield P 4O10 = 17.9g mass yield H 2O = 4.80g. What is the empirical formula of the compound  PH 2.

GENERAL CHEMISTRY

mass compound sample with C,H,O = 0.95g , when fully combusted in oxygen gives mass H 2O = 0.518g . mass CO 2 = 2.13g . What is the simplest or empirical formula. C 5 H 6 O2.

 Naturally occurring Ga is composed of 60% Ga-69 and 40% Ga-71 atomic mass Ga-69 = 68.911 atomic mass Ga-71 = 70.931. Calculate the average atomic mass of Ga 69.72amu. roasting of 100g of copper ore yields 75.4g of 89.5% pure copper . If the ore is composed of Cu 2S and CuS with 11% inert impurity, calculate the  percentage of Cu2S in the ore . 62%.

wt % sand = 70, wt % water = 30 density pure quartz = 165 lb/ft 3 . What is the density of the mud, the sand is practically pure quartz 110.4 lb/ft 3,

[HBr] = 0.1 V HBr = 50 m l [KOH] titrant = 0.1M V base = 49mL. Calculate the pH after the volume of base has been added to 50 ml of HBr 3.0 [HCl] = 0.0015M . What is the concentration of OH in water solution 6.7E12M  [HCl] = 0.10M volume HCl = 50.0ml [NaOH] = 0.20M, volume NaOH = 100ml . What is the pH of the resulting solution 13 [HCN] = 0.100M Ka HCN = 7.2E-10 . What is the pH of a solution 5.1 [HF solution] = 0.1M % dissociation = 9.5%. Calculate the K a for HF 1.0E-3. [hydronium ion] = 2E-3M . What is the pH the a solution 2.7 [Mg2+] = 0.001M Ksp Mg(OH) 2  = 1.2E-11 . Calculate the pH of a solution necessary to just begin the precipitation of Mg(OH) 2 10 [NaOH] = 0.100M V NaOH = 180 ml [HAcetic] = 0.100, V acetic = 200 ml K a  acetic acid = 1.8E-5 . What is the pH of a buffer prepared by adding NaOH to acetic acid 5.70 [NH3] = 0.0500M Kb NH3 = 1.8E-5 . What is the pH of a solution 11.0 [NH4Cl] = 0.256M [NH 3] = 1.8E-5 . What is the pH of NH 4Cl 4.92 A metal reacts with water with the evolution of hydrogen and formation of its hydroxide. mass metal = 1 g atom (the chloride of metal was found to contain 13.7% chlorine) volume OH solution = 1L [HCl]= 0.9091N volume HCl = 110ml. The volume of hydrogen gas liberated at STP 11.2. The atomic weight of the metal 224. Since the solution of the OH of the metal is normal, the valency of the metal is 1.  buffer pH= 4.0 Ka benzoic acid = 6.5E-5. Which of the following solutions results in a the given buffer 0.16M benzoate and 0.25M benzoic acid. C(s) + CO 2 = CO(g) Kc = 1.6, equilibrium concentration of CO 2 = 0.5M . What is the equilibrium concentration of CO. 0.89 H2 + I2 = HI Kc for HI equilibrium@425C = 54.5, [H 2]0  = 0.00623M [I2]0 = 0.00414M [HI]0 = 0.0224M . Calculate the concentration of I 2 in equilibrium 0.00267M.

Ka HCN = 7.2E-10 . What is the ratio of acid concentration to anion concentration needed to produce a buffer of pH 10.0 using HCN and NaCN. 0.14 mass acid = 1.243g volume = 31.72 cm3 of 0.1923N. What is the equivalent weight of an acid of standard base for neutralization. 204 mass CaCO3  = 1.0kg . The maximum number of kilograms of CaO  produced on heating 0.56kg. mass impure sample Na2CO3 = 1.2048g (is dissolved and allowed to react with a CaCl2  solution) mass of resulting precipitate CaCO 3  = 1.0362g . Assuming that the impurities do not contribute to the weight of the  precipitate, calculate the percent purity of the Na2CO3. C% mass of impure ammonium aluminum sulfate = 759.08mg, the aluminum in the sample was precipitated as Al(OH) 3  and ignited at 1100C to yield Al 2O3mass Al2O3 = 387.953mg . Express the result of analysis in terms of %Al 27%. mass of KHP = 1.431g necessary in standardizing a solution of NaOH, mass alkali = 25.5ml mass acidrun back  = 8.25ml (1ml=10.75 NaOH). What is the molarity of the NaOH solution 0.2598. mass sample (containing Al(NO 3)3, AlCl3, and inert) = 1.7483g (divided into two equal portions) Case 1: portion [AgNO 3]titrant = 0.1M V AgNO 3 = 50mL excess was titrated back with 28.89ml of 0.1002 M KSCN for titration Case 2: portion 2, [NaOH] titrant = 0.1193M V NaOH = 26.02 ml to completely precipitate as Al(OH) 3  . Calculate the % AlCl 3 in the sample 10.70%. mass sample (Na2CO3, NaHCO3, inert) = 1.179g, titrated acid= 0.1N, HCl volume acid = 24ml, indicator = phenolphthalein . Another duplicate sample was titrated with HCl; using methyl red as indicator. It required 50.25ml of the acid for color change. What is the % NaHCO 3 in the sample. 18.7. mass sample = 253.02mg containing NaBr and KBr was dissolved in water and treated with AgNO 3 mass precipitate = 429.85mg. Calculate the %NBr in a sample 49%. mass sample crude ammonium salt = 1.00g (treated with hot KOH solution) [acid] = 0.5N V acid= 50mL [NaOH] = 0.2N, 3.12 mL for neutralization . Calculate the %NH3 in the sample 41.25% mass sample mixture (NaOH, Na 2CO3, inert impurity) = 1.2g [HCl] titer = 0.5M indicator = phenolphthalein . the solution turns colorless after the addition of 30ml of the acid as a required for the color change to pink. Methyl orange is then added and 5ml more of the acid are needed to color change. What is the % Na 2CO3 in the sample. 22.08 mass sample of impure AlCl 3  = 1.500g was dissolved in water and treated with AgNO3 using Mohr method [AgNO 3]titrant = 0.1000M V AgNO 3 = 45.32ml . Determine its purity AlCl 3 (133.33 g/mol) 13.43%. mass vinegar = 3g titrated acid = 0.115N KOH, volume acid = 20.50ml indicator = phenolphthalein. What is the percentage of the total acid expressed as acetic acid in a sample of vinegar for an end point with the given indicator 6.72%. mole AgCN = 0.0010 volume = 1L K HCN = 4E-10, Ksp AgCN = 1.6E14 . What (H +) is needed to dissolve completely AgCN 0.025M  n ammonia = 0.25 mol K  b  = 1.8E-5 . What is the pH of a solution  prepared from ammonia dissolved in sufficient water to make 1L solution 11.33.  pH buffer = 5 . What is the ratio of the concentration of acetic acid to sodium acetate 0.56 solubility barium sulphate = 0.0091g/L @ 25C MW barium sulphate = 233g/mol . What is the solubility product constant of barium sulphate. 1.523E-9. sp.gr HCl solution (23.81%wt. HCl)= 1.12. How many grams of HCl are  present in each milliliter solution. 0.27 volume of 0.1N NaOH= 10ml volume of 0.1N HAc= 25ml Calculate the  pH of the solution 4.57. What are the percentages by mass of each element in CaCl 2. 36.1%Ca and 63.9% Cl.

mass alkane = 2.2g mass bromine = 3.2g . The molecular formula of A C 8 H 16, moles alkane = I mole, moles water = 7 moles . an alkane reacts with excess O2 to give water. The alkane could be hexane. moles alkane = I mole, moles water = 7 moles . moles of CO2 generated from the same alkane 6. saponification number of triglyceride = 200 . Average MW of triglyceride 840.

Ammonium iodide dissociates reversibly to ammonia and hydrogen iodide. NH4(s)↔ NH3(g) + HI(g) K  p  @ 400C = 0.215. If 150g of ammonium iodide is placed into a 3-L vessel and heated to 400C, calculate the partial pressure of ammonia when equilibrium is reached. 0.46 atm. angstrom = 3.92 face-centered cubic crystal density = 21.5 g/ml . What is its atomic weight 195. At volume vessel 1 = 1L established equilibrium with the rxn: 2SO 2 + O2 = 2 SO3 mol SO2 = 0.11 mol O2 = 0.05 mol SO 3 = 0.12 @volume vessel 2 = 1L mass SO2 = 96g initially. How much O 2 (in grams) must be added, if at equilibrium, one half of SO 2 will be converted to SO 3 13.34. Calculate the root mean square speed of a helium atom at 298K 1363 m/s charge = 8.5E3coulombs . How many grams of iron (Fe) could be deposited from a solution of FeCl 2 2.46. D tube = 3mm Length tube = 78.74 inches, Pressure head = 6.5 N/cm 2, volume fluid = 0.04 m 3 passes through the tube every 1 minute. What is the viscosity of the fluid. 0.097cP. E = 75,000 cal/mol (pyrolysis of ethane). How much faster is the decomposition at 650C than at 500C. 2795 times faster. electrical current = 10 amperes . What is the mass of aluminum produced in 1 hour in the electrolysis of molten aluminum sulfate 3.36g. t1/2 of radioactive isotope C-14 = 5720 years mass of sample carbon = 1.00g undergoes 15 disintegrations per minute per gram. How old is a 10.0g sample for which the rate i s 0.91 disintegrations per minute per gram 4120  years. frequency: 5.11E+11 Hz . What is the wavelength of radiation 5.87E-4 m. heat of combustion methanol = -173.7 kcal/mol @18C, heat of combustion CO = -67.6 kcal/mol @ 18Cn heat of formation of H 2O(l) = -68.4 kcl/mol . Find the heat of reaction at 18C for CO(g) + 2H 2(g) = CH 3OH(l) -30.7  kcal. mass calcium nitrate = 11.3g mass water = 115g . What is the freezing  point of a solution -3.34C  mass defect for the triton (tritium nucleus) = 0.00910amu. Calculate the  binding energy per nucleon 2.825 MeV. mass Fe(s) = 1.67g t = 1.00 hour . What current would be necessary to deposit Fe(s) from a solution of Fe3+ (aq) 2.40A. mass gas density bulb evacuated/empty  = 29.3215g mass bulb with CO2  gas @40C, 1 atm = 30.0079g mass bulb with CO and CO 2  at same T&P = 29.9332g . Determine the % of CO in the mixture 29.9. mass hydrogen= 0.504g time the current is liberated= 2 hours. How many grams of copper can be liberated by t he same current flowing for the same time in a copper sulfate solution. 15.9. mass isotope = 1 g t 1/2 isotope = 15 hours . The half-life of 0.50g sample 15 hours. mass isotope = 1g t 1/2 = 15 hours . The half life of 0.50g sample 7.5 hours. mass metal = 400g heated to =96.5C mass H 2O at calorimeter = 2000g @20C Tf  = 21.5C . What is the specific heat of the metal in cal/g.C 0.10 mass N2O4 = 1.588g total pressure = 1.0133 bar, volume glass vessel @ 25C = 500 cm 3 . What is the value of Kp. 0.143 bar.

mass of flask evacuated = 134.567g pressure gas = 735torr @ 310C, mass of flask after filling with gas @ given P and T = 137.456g mass of flask filled with water@31C = 1067.9g . Assuming ideal gas equation applies, calculate the molar mass of the unknown gas 79.7. mole Cl2  = 1.00 mol V = 1.00L T = 200K, a=0.493L 2-atm/mol2  b=0.5622 L/mol . What is the pressure calculated by van der waals equation 31.0 atm. moles of electrons = 3.00 potential = 1.74 V, What is the electrical work done 5.07E5J. PCl3(g)        PCl3(g) + Cl2(g), dissociates, T = 250C P = 1 atm heat 

density = 4.4g/L at equilibrium . The fraction of PCl5 dissociated is 0.103. T = 25C . The difference between the heat of combustion of methane at constant pressure and at constant volume when liquid water forms -1257.4 cal. T = 27C . The difference between the heat of combustion of methane at constant pressure and at constant volume at the given temperature when the liquid water forms. -1192.2 cal. T1 = 20C T2 = 100C electric current = 10A, voltage = 10V t = 10 hours. Calculate the mass of water in grams that could be heated 10,755. viscosity coeff of gaseous Cl = 147.0 micropoise @ 20C. Find the molecular diameter of the chlorine molecule. 4.22E-8cm. volume 1 methane= 200ml Temperature= -42C, volume 2 methane= 100ml . Find the final temperature 74. volume gas mixture (N 2  and CO 2) = 10.0 L (with 3.00g N 2), PT = 0.750atm\ T = 273K . What is the partial pressure of CO 2(g) in the mixture. 0.510 atm. VP pure benzene @ 25C = 0.1252 atm ma ss unknown HC= 6.4g mass,  pure benzene (MW=78) = 78g VP benzene in solution = 0.1192 atm . What is the molar weight of the unknown solid. 128. VP pure ethyl alcohol @ 30C = 71.2 torr VP pure carbon tetrachloride = 121.6 torr mass ethyl alcohol = 20g mass carbon tetrachloride = 60g . Calculate the pressure above a solution assuming ideal behavior 95.0 torr. Z = 2.50 @ 65.0 atm n gas = 2.00 moles, V gas = 1.00L P = 65.0 atm. What is the temperature of this gas 158K.

a closed gaseous system undergoes a reversible process Qrejected = 25 BTU V1 = 5ft 3 V2 = 2ft 3 P = (constant) 50psia. Find delta U 2.76 BTU. heat content of 70% NaOH liquor @ 160F = 325 btu/lb is diluted with 20% NaOH liquor @ 80F heat content 20% NaOH liquor = 40 btu/lb heat content final solution, 40% NaOH = 94 btu/lb . For every 100lb  product, how much heat must be removed to maintain a final product temperature of 100F. 6000 btu. heat engine absorbs heat from the combustion of gasoline @ T=2200C, sp.gr of gasoline = 0.8 heat combustion = 11,200 calories per gram T = 1200C, engine rejects heat . The maximum work in calories that can be obtained from the combustion of 1L gasoline 3.26E6 cal. heat of combustion benzoic acid = -770.9 kcal/mol (measured in bomb calorimeter) @ 25C . Find the heat of combustion of benzoic acid in kcal/mol at 25C in a stream of oxygen assuming complete condensation of water vapor to liquid -771.2. helium is compressed isothermally P= 14.7 psia, T = 68 F compression ratio = 4 . Determine the change in entropy of the gas in BTU/lb-F 0.689. mass Cu = 5lb T = 200F mass water = 10lb m . Copper is submerged in water and after a period of time, equilibrium is established. What is the entropy change of the system. 0.0167 BTU/R. mass ice cubes = 5 lbs (manufacture from water initially at 32F) T, surrounding air = 80F latent heat of fusion of water = 143.4 btu/lb. The minimum work 70.0 btu.

mass of ice = 100g. T 1 = 0C (ice) T2 = 100 C @ 1 atm (steam) . Calculate the change in entropy in converting ice to steam 205.28eu. mass of oxygen gas = 8 grams @ 27C, 10 atm and expands adiabatically and reversibly P final = 1.0 atm . The work done in the process -752 J. moles of ideal gas= 3 @ P = 1 atm @ T = 20C, heated at constant  pressure T final  = 80C C v  = 7.50 + 3.2E-2T, cal/mol.K. The change in internal energy of the process is 3210.50 cal. P1 = 1 bar (initial condition air is compressed) @ 25C, P 2 = 5 bars @ 25C . Assume air is ideal gas, calculate the work done in J/mol 3990. Calculate the heat required in J/mol -3990. P1 = 200kPa P 2 = 150 kPa . For an ideal gas, what is the specific molar entropy change during an isothermal process. 2.39 J/mol-K. Psat steam = 350 kPa mixed with water at 15C Thot water  = (produced from mixing) 80C rate mixing = 4 kg/s internal diameter = 50mm (inlet and outlet lines to the mi xing device) . At what rate must steam be supplied 0.41 kg/s. Q = 1055kJ T = 427C (heat engine absorbs heat), T = 38C (heat engine rejects heat) . The work done in kJ by the engine if its efficiency is 50% of the carnot engine is closest to 496.6kJ. Qabsorb = 1055kJ @ T =427C, T reject = 38C . The work done in kJ by the engine if its efficiency is 50% of the Carnot efficiency is closest to 293.3 kJ. refrigerator capacity = 3140 watts input rating = 735 watts. The coefficient of performance of the refrigerator is 4.27. T = 100C (water evaporates) @ 1 at m . Calculate the work done by the system in which 1 kmole of water evaporated 3060 kJ. Tsteam = 212F mass water = 400lb, T water  = 70F heat losses = 2000 Btu . Find the amount of steam to make the T F of water to be 212F 60.6 lb. two carnot engines are operating in series. T1 (absorbs) = 1,111K T 2 (rejects), the second engine receives the heat at the intermediate temperature T and rejects it to Treservoir  T reservoir  = 300K . Calculate T if the efficiencies of the two engines are equal. 577K  Required 2: From the data above, calculate T i f the work done by the two engines are equal. 705K. VP acetic acid @ 90C = 293 mmHg VP acetic acid @ 100C = 417 mmHg . Calculate the normal boiling point of acetic acid 391.3K.

A fixture containing an ordinary incandescent light bulb is connected to a dimmer switch. Temperature of the tungsten filament inside the  bulb increases from 1300K- 2600K. Total Power radiated by the bulb.  Increase 16x A heat exchanger is required to c ool 20kg/s of water. T= 360K to 340K. m=25kg/s. Tentering water = 300K. Overall coefficient of heat transfer= 2 kW/m2-K.Calculate the surface area required in a counter concentric tube exchanger. 20m2 A method where engineers assure the existence of an exchanger and make calculations to determine if the exchanger would handle the  process. Rate an exchanger A popular type of heat exchanger for cooling large quantities of fluid.  Low thermal conductivity A reaction mixture,Cp= 2.85 kJ/kg-K, flowing at a rate= 7260kg/hr. to be cooled from 377.6K to 344.3K. Tcooling water= 288.8K, flow rate= 4536kg/hr. OHTC= 653 W/m 2-K.Calculate the outlet water temperature. 51.95°C A single 4-in steel pipe, OD = 4.5 inch, outer surface temperature= 300°F. The horizontal pipe in a large room with ambient temperature= 78°F at standard barometer. The heat total (natural convection and radiation) for 25ft of length in Btu/hr. 21100 Air Tin=75°C, Tout= 225°F. Hot gas: T out= 265°F. LMTD= 140°F. Find the temperature of the hot gas entering. 325°F An economizer receives hot gas (Cp=0.27 BTU/lb-°R) and water in the ratio of 1.5 lb gas per lb water. Tgas in= 850°C. Tgas out= 355°F. Twater in= 120°F. Find the exit temperature of the water if the flow is parallel. 320°F An insulator should have. Low thermal conductivity Benzene at 100°F and 1 atm flows at 100ft3/min in a smooth 1” ID tube. The heat transfer coefficient for the system in BTU/ sec-ft2-°F Calculate the inside area of the coil in ft2. 2.664 4. Calculate the gpm of water cooled. 0.380 Composite wall at 2000°F. Outside ambient temperature at 70°F. Three layers composite wall, 12, 12 and 10 inches. Thermal conductivities: 0.4,0.2 and 0.1BTU/hr-ft-°F. Inside heat transfer is negligible. Outside air film heat transfer coefficient is 2BTU/hr-ft2-°F. Heat loss through the composite wall in BTU/hr-ft 2 is. 118.2 Composite wall composed of 2” cork on the inside, 6” concrete and 3” wool on the outside. Thermal conductivities= 0.025,0.8 and 0.065 BTU/ hr-ft-°F. Inside surface temperature= 40°F. outside t emp=78°F. What is the heat flux through the wall in BTU/hr-ft 2. 3.41

Determine the rate of conduction of copper rod. Diameter= 2mm, Length= 150 mm. Temperatures: 300°C at one end and 20°C at the other end. Ave. thermal conductivity= 1.36E6 J/s-m-K. 7890W Determine the temperature (in °F) at the junction between the firebrick and the insulating brick. 1533 Determine the temperature (in °F) at the junction between the insulating  brick and common brick. 328 6.Calculate the heat loss per linear foot from 2in nominal pipe (2.375 in outside diam eter). Covered with 1 inch of an insulating material. average thermal conductivity= 0.0375 BTU/hr-ft-°F. Temperatures of the insulation= 390°F and 80°F. 120BTU/hr-ft Dittus-Boelter equation for the determination of heat transfer coeff. is valid. For fluids in turbulent flow Film and drop are the terms associated with. Condensation Find the thermal conductivity of a 0.5m thick material with an area of 5m2 and a temperature difference of 10K if the heat transmitted during 2hrs of test is 2000kJ. 2.78 W/m-K Flat wall with 6inch layer firebrick( k=0.95BTU/ hr-ft-°F), 4inches insulating brick (k=0.14), and 4inches common brick (k=0.8). Firewall temperature= 1800°F, outer surface temperature= 120°F. The heat loss through the wall in BTU/hr-ft 2. 506 Heat loss (W/m2) by radiation & convection from an unlagged horizontal steam pipe, 50mm, od. At 377K. Air at 283K. 1587 Heat transfer area for a natural convection. Horizontal pipe diameter= 0.15m. Surface temperature of 400K to air at 294K. 6.81 W/m2-K Convection coefficient of heat transfer of nickel wire(0.035 in diameter at 1700°F) to air is equal t o 6 BTU/ hr-ft 2-°F. How much heat is lost by 1ft of wire inside an oxidized copper container, the air and container  being 160°F. 85BTU/hr Hollow metal sphere. Inside wall temperature= 300°F. Internal diameter= 6 inches and 2inch thick. Outer surface= 212°F. Thermal conductivity of metal= 8BTU/hr-ft-°F. What is the heat loss from the sphere. 5529BTU/hr Hollow sphere. Outside radius= 1m made up of polystyrene foam. Thickness= 1cm. the inner surface is 5.20°C hotter than the outside surface. Thermal conductivity of polystyrene foam= 0.033 W/m-°C. The power produced by the heat source. 214 W How much part of the light is absorbed by the body that t ransmits and reflects 80% and 10% respectively. 10% If a man touches two metals which were kept together at room temperature, why would one metal feel colder than the other. One has higher thermal conductivity In a heat transfer equipment, dirt or scale may be accounted by introducing a resistance called. Fouling factors In a steady state heat t ransfer through a series of materials with varying resistance, the heat transfer.  Is constant throughout the series of materials In convection heat transfer, the mechanism of heat transfer where the fluid moves due to the decrease in its density caused by increased in temperature. Natural convection In heat exchanger the area of heat transfer is calculated from. The total lateral area of the tubes LMTD. 230°F Metal rod= 10cm long, diameter= 2cm. One end is in contact with steam at 100°C while the other end is in contact with ice at 0°C. 320g of ice melted after 20 mins. The thermal conductivity is. 283.6 W/m-K  Methyl alcohol flowing in the inner pipe of a double pipe exchanger is cooled with water flowing in the jacket. Inner pipe= 1-inch(25mm), Sched 40 steel pipe. Steel thermal conductivity= 26 BTU/hr-ft-°F(45 W/m- °C). hi = 180 BTU/hr-ft 2-°F(1020 W/m 2-°C), hdi= 1000 BTU/ hrft2-°F (5680 W/m 2-°C), ho= 600 BTU/ hr-ft 2-°F(3402 W/m 2-°C), hdo= 500 BTU/hr-ft 2-°F(2840 W/m 2-°C). What is the overall heat transfer coefficient based on the outside area of the inner pipe in BTU/hr-ft 2-°F). 80.9

Pipe diameter= 50mm with circular section with walls 3mm thick covered with two concentric layers of lagging. Inner layer thickness= 25mm with thermal conductivity= 0.08 W/m-K. outer layer thickness= 40mm with thermal conductivity= 0.04 W/m-K. What is the rate of heat  per meter length of pipe. Ti= 550K, T o surface temp= 330K. 62.7W/m Ratio of the molecular diffusivity and momentum in liquid is known as the. Prandtl no. Refractory material… Emissivity of 0.40 at 1500K and 0.43 at1420K. Temperature of 1420K exposed to black furnace walls at 1500K. The rate of gain of heat by radiation per unit area in Kw/m 2. 24.3 Stack gases leave a boiler, pa ss through a square steel duct 3ft by 3ft and 16ft long. And enter a masonry chimney. Estimate the heat transfer coefficient (in BTU/hr-ft2-°F) in the duct if the gases are at 900°F and 1 atm. Consider the stack gases to have the same properties as air. The gas velocity is 50ft/sec. Steam pipe. Outside diameter= 2inches. Inside surface temperature= 350°F. pipe coating material= 2inch thick. Thermal conductivity: k= 0.5 + 5E-4T in °F. k in BTU/hr-ft-°F. Outside surface coating= 100°F. Calculate the heat loss per foot of pipe length. 877 BTU/hr  Surface temperature is. 129.1°F  The area assuming it’s co-current. 6.46m2 The area assuming it’s counter current. 5.43m2 The inside and outside surfaces of window glass are 20°C and -5°C. Glass: 100cm by 50cm in size and 1.5cm thick. Thermal conductivity= 0.78 W/m-K. Heat loss through the glass at 2hrs. 1.30kWh The main trunk duct of an air conditioning system is rectangular in cross-section(16in x 30in) and has air at 15psia and 40°F flowing through it with velocity of 1400 fpm. Find hi in BTU/ hr-ft 2-°F. 4.50 The mode of heat transfer that can take place in a vacuum.  Radiation The overall conductance for a composite material in series is equal to the. Inverse of the total resistance The total heat loss by radiation and convection from unlagged horizontal steram pipe of 50mm diameter at 415K at air= 290K. 384W/m The transfer of heat through and by means of matter. Conduction The view factor F21 of a sphere(1) of diameter D inside a cubical  box(2) of length L which is equal to D is. 0.524 Two very large walls at constant temperatures (800°F and 1000°F). Emissivities: 0.6 & 0.8. Net exchange heat in BTU/hr-ft 2. 1825 Water cooler uses 50lb/hr of melting ice to cool running water from 80°F to 42°F. Ui= 110 BTU/hr-ft 2-°F. Find the LMTD. 24.24 °F What is the reason why Styrofoam is a good insulating material.  Because it contains many tiny air pockets of air

2000kg/h of a mixture consisting of 60%wt benzene and 40%wt toluene is to be separated in a distillation column. The distillate is to contain 98%wt benzene and 95% of the feed benzene is to be recovered as distillate. what is the flow rate of the distillate. 1163kg/h 41.78o Be is equivalent to 42.12 oAPI. A contract was made between a buyer and a paper manufacturer for  paper containing 5% moisture at P450/ton on specification that price adjustment will be made if the quality is different. How much should the buyer pay for 1 ton of paper with 8% moisture content. Freight cost is P45/ton. P434.16 A dehumidifier sprays 50lb/min of cold water into a stream of air. 100lb/min of wet air enters the dehumidifying chamber. The absolute humidity of the entering air is 0.05lbwater/lb d.a. What is the total of the liquid water leaving the chamber per minute. 53.81 A mixing tank mixes two inlet streams containing salt. The salt concentration in stream 1 is 5% by weight and in stream 2 15% by

weight. S1 flows at 25kg/s while S2 at 10kg/s. there is only one exit stream. Find the salt concentration in the exit. 8% A solution of gravity of 100 o Twadell. Calculate the specific gravity in degrees Baume. 48.33 A typical mud is 70 wt% sand and 30% wt water. What is its density. The sand is practically pure quartz (SiO 2) for which its density is 165 lb/ft3. 110.4lb/ft 3 Ethylene reacts with water to form ethyl alcohol. If 20g of each reactant is used, 20g of alcohol is produced. What is the percent yield. 60.9% Fresh orange juice contains 12%wt solids. Initially a single evaporation  process was used for the concentration to 45%wt but volatile constituents of the juice escaped with water, leaving the concentration with a flat taste. The present process overcomes this problem by  bypassing the evaporator with a fraction of the fresh juice; the juice that enters the evaporator is concentrated to 58% solids and the product is mixed with the bypassed fresh juice to achieve the desired final concentration of solids. Calculate the fraction of t he feed that bypassed the evaporator. 10% From data above, calculate the %benzene in the bottom. 7.2% From the data above, calculate the flow rate of the bottom product. 837kg/h H2 gas can be prepared by the reacti on of zinc metal with HCl solution according to the equation: Zn + 2HCl  ZnCl2 + H 2 How many liters of H2  gas will be formed at 762mmHg and 15 oC if 25.5g Zn was allowed to react with HCl. 9.44L How many pounds/day of CaF 2 is needed t o produce 3000lb of a 60% HF acid/day if the yield is 90% and the rock contains 95% pure CaF 2. 4105.2 One dried will dry a material from 45% (wb) to 20% (db). From here, the material enters another drier where the water content is further reduced to give a final product weighing 1000kg. if the total evaporated water from both driers is 800 kg, the moisture content (wb) of the final  product is 1%. Pig iron is prepared in a blast furnace from a hematite ore. The ore contains 83% ferric oxide. The pig iron produced is 96% Fe and the Fe in the ore slag contains 10% of t he iron in the ore. How much pig iron is produced for every 500tons of ore. 272 tons The CO2 that will theoretically be formed when a mixture of 50g of methane and 100g oxygen is ignited is 68.8g. The equivalent of 45 oTw in the Baume scale is 26.63 The waste acid from a nitration plant operation contains 23% HNO 2, 57% H2SO4  and 20%H2O. It is specified that the concentrated acid  product contains 27%HNO2, 60% H 2SO4 and 13% water. If the H 2SO4 available contains 7%H2O and the HNO 2  contains 10% water, how many lbs of the waste acid is needed to produce 1000lb of the product. 418.3lb

A fuel containing 75% ethane and 25% propane is burned with dry air. All the H2 burns to water and CO 2 to CO ratio is 10:1. 15% excess air is supplied. Calculate a) mole stack gas/ 100 mole fuel; b) Orsat analysis of stack gas; c) complete analysis of stack gas; d) m3 dry air at 28C and 765mmhg per mole fuel. a. 2294.75 moles, b. %CO= 1.038% %CO2=10.38%, O2=3.47%, N 2= 85.11%, c. –   , d. 0.521m3 /mol  A fuel containing methane and ethane is burned with excess air. The analysis of the dry stack gas is given as follows: 4.62%CO2, 3.08%CO, 8.91%O2 and 83.39%N 2. Determine the %excess air. 49.81% A furnace is fired with petroleum containing 80%C, 13%H, 3%S, 1%N and 3%O. Determine the moles of theo air required for the complete combustion of 1kg of oil. 472

A pure saturated hydrocarbon is burned with excess air. The analysis of the product of combustion shows 9.08%CO 2, 1.63%CO, 5.28%O 2 and no free H 2. Determine the hydrocarbon C 3 H 8. A pure saturated hydrocarbon is burnt with excess air. Orsat analysis of the stack gas shows 7.9% CO 2, 1.18%CO, 0.24% H 2 and 85.43% N 2. Air is substantially dry. The stack gases leaves at 750mmHg. Dry air required for the burning of 1ft 3 of CO is 2.4ft 3. From the data above, determine the mole percent of ethane in the fuel. 18.57% If the test study on the combustion of the cetane-methyl naphthalene mixture gave a product analysing 7.14% CO 2 4.28% CO 8.24%O 2 and the rest N2, what is the cetane number of the diesel. Density of cetane is 0.775g/ml and n-heptane is 0.684g/ml. 44.71 The analysis of flue gas from a fuel gas is containing no nitrogen is 4.62%CO2, 3.08%CO, 8.91% O 2 and 83.39% N 2. Calculate the %excess air if all the fuel is burned. 50

100 lb of sodium carbonate in water at 10C to 30C. 185lb 100lb Sodium sulphate at 40C cooled to 5C. 69.5lb 13% K 2Cr 2O7 from 1000 lb soln cooled to 20C with 640 evaporated water. 103.6lb A solution of NaNO 3 in water at 40C contains 49% NaNO3 by weight. 92% Ammonium chloride at 70C cooled to crystallize 45% of the solution. 9.5% From above %yield is 95%. From above, % yield is 10.8%. From above, concentration of NaNO 3 per 100g water. 81.8g From above, molality of the solution is 9.64m. From above, molarity of the solution is 7M. From above, percent yield. 80% From above, weight sodium nitrate cooled to 0C. 4.84g From problem above, weight NaNO 3 from 1000lbs by reducing temperature to 10C. 82 Percent yield of the process above. 16.8% Sodium nitrate at 60C contains 45% sodium nitrate. % saturation is 66%.

1000lb pile of mixture of 20% sand and 80%KCl. Drained solids a fter 1st  leach is 1206lb. Drained solids after 2nd  leach is 253.9 solids. %KCl= 27% or 21%. Collective drained solids is 2806lbs. %KCl from collective= 28.37%. A solvent extraction will be performed on a solid B that contains a soluble component A (Xa= 0.25 Xb=0.75). Lb solute A/lb A&B to obtain 95% A is 1.67%. How many stages and how much water is needed for the countercurrent extraction of NaOH of feed of 80lb NaOH,400lb water and 100lbCaCO3. 580lb, 3.14~4stages. Roasted copper ore with 10%CuSO 4 85% gangue and 5% moisture. Percent CuSO4 underflow 0.13%. %Recovery is 97.96%.

a cooling coil, consisting of a single length of tubing through which water is circulated, is provided in a reaction vessel, the contents of which are ket uniformly at 360K by means of a stirrer. T inlet cooling water  = 280K, Toutlet cooling water  = 320K. What would be the outlet water temperature if the length of the cooling coil were increased by 5 times. Assume the overall heat transfer coefficient to be constant over the length of the tube and independent of the water temperature. 357.5K  a shell-and-tube heat exchanger consists of 120 tubes of internal diameter 22mm and length 2.5m. It is operated as a single pass condenser with benzene condensing at 350K on the outside of the t ubes and water of inlet temperature 290K passing through the tubes. Initially there is no scale on the walls, rate of condensation = 4 kg/s, water velocity = 0.7m/s, scale resisitance = 0.0002m 2-K/W (formed on the inner surface of the tubes), latent heat of vaporization benzene = 400kJ/kg. To what value must the water velocity be increased in order to maintain the same rate of condensation on assumption that the transfer coefficient on the water side is proportional to the velocity raised to the 0.8 power, and that the coefficient for the condensing vapor is 2.52 kW/m2-K, based on the inside area. 2.06m/s a shell-and-tube heat exchanger is used for preheating the feed to an evaporator. liquid specific heat = 4.0kJ/kg-K, density liquid = 1100 kg/m3, Tsteam condensing = 395K on the outside The exchanger heats liquid at 295K to an outlet temperature of 375K when the flowrate is 1.75x10-4

m3/s and to 370K when the flowrate is 3.25x10E-4 m 3/s. What is the heat transfer area and the value of the overall coefficient when the flow rate is 1.75x10-4 m 3/s. 0.136kW/m2; 9.09m2 a thermometer is immersed in a liquid which is heated at the rate of 0.05K/s, Uto the bulb = 735 u 0.8 W/m 2-K, area of the bulb = 0.01m 2. If the thermometer and the liquid are both initially at 290K, what rate of  passage of liquid over the bulb of the thermometer is required if the error in the thermometer reading after 600s is to be no more than 1 deg K. Take the water equivalent of the thermometer as 30g. 0.82 m/s  benzene is to be condensed in a vertical shell and tube type of heat exchanger fitted with tubes of 25mm outside diameter and 2.5 long, rate = 1.25kg/s, *vapor condenses on the outside of the tubes, T cooling water enter = 295K, rate cooling water = 1.05 m/s, tube wall thickness = 1.6mm. Calculate the number of tubes required if the heat exchanger is arranged for single pass of the cooling water. 60 tubes are required Calculate the time for the distant face to reach 470K under the same conditions as, except that the distant face is not perfectly lagged but a very large thickness of material of the same thermal properties as the  brickwork i s stacked against it. t=2.26x10E5 s or 0.226 Ms (62.8h; t=2.38x10E5s or 0.238 Ms (66.1h) co-current flow cooler, T 1 oil  = 370K, T 2 oil  = 350K, *temperature is reduced by lengthening the cooler, T water enter = 285K, Toil enter = 420K, Twater leaving = 310K (original cooler), *the oil and water flowrates, inlet temperatures and other dimensions of the cooler will remain constant. If the original length is 1m, what must be the new length. 1.86m countercurrent-flow heat exchanger, benzene is cooled using water, mass flow rate benzene = 1.25kg/s, density benzene = 880 kg/m 3, specific heat benzene = 1.9 kJ/kg-K, T 1 = 350K, T 2 = 300K, T water  = 290K, external diameter heat exchanger = 25mm, internal diameter heat exchanger = 22mm, *water passes through the tubes, film coefficient water = 0.85kW/m2-K, film coefficient benzene = 1.70 kW/m2-K, *scale resistance is neglected. What total length of tube will  be required if the minimum quantity of water is to be used and its temperature is not to be allowed to rise above 320K. 165.8m Density HC = 950 kg/m 3; Specific heat capacity = 2.5 kJ/kg.K; T 1 HC = 363 K; T 2HC = 313 K; T 1 water = 293 K; T 2 water = 323 K; flowrate HC = 0.56 kg/s HC is cooled in heat exchanger with water countercurrently. What is the required flowrate of water. G=0.56 kg/s. After plant modifications, the heat exchanger is incorrectly connected so that the two streams are in co-current flow. What are the new outlet temperatures of HC and water, if the overall heat transfer coefficient is unchanged. 324.2 K; 315.8K depth longitudinal fin = 75mm, thickness fin = 3mm, T pipe surface = 400K, coefficient of heat transfer surface  = 5W/m2(constant), thermal conductivity fin = 50W/m-K, T base of t he fin  = 400K. Calculate the heat dissipated per meter length from the fin to the atmosphere at 290K, the heat loss from the extreme edge of the fin may be neglected. 6.23 W/m diameter cast-iron vessel = 1m, diameter propeller agitator = 0.3m, frequency propeller = 2 Hz, mass flow rate circulat ing cooling water = 0.5 kg/s, outside diameter steel coil = 25mm, inside diameter steel coil = 22mm, diameter helix = 0.81 m, mean water temperature = 290K *the conditions are such that the reacting material may be considered to have the same physical properties as 75% sulphuric acid/ What is the overall heat transfer coefficient. 458.7 W/m2-K diameter one end of metal bar = 25mm, length bar = 0.3 m, T bar  = 375K, *heat is dissipated from the whole length of the bar to surroundings at 295K, coefficient of heat transfer from the surface = 10 W/m 2, thermal conductivity metal = 85 W/m-K. What is the rate of loss of heat. 12.5 W Diameter open bowl = 0.3 mm; T=350K (evaporating water into the atmosphere); mass water = 10 kg. If the air currents are sufficiently strong to remove the water vapor as it is formed and if the resistance to its mass transfer in air is equivalent to that of a 1mm layer for

conditions of molecular diffusion, what will be the rate of cooling due to evaporation. 0.026 deg K/s diameter open cylindrical tank = 500mm,depth tank = 1 m (three quarters filled with a liquid),liquid density = 980 kg/m 3, specific heat capacity = 3 kJ/kg-k, overall heat transfer coefficient for the coil = 100 W/m2-K, Tsurrounding  = 288K. If the heat transfer coefficient from the cylindrical walls and the base of the tank is 10 W/m 2-K and from the surface is 20 W/m 2-K, what area of heating coil, fed with steam at 383K, is required to heat the contents from 288K to 368K in half hour. 5.0m2 dimension rectangular ingot = 15cm x 15cm x 30cm, T initial of ingot = 290K, T = 1400K (silica brick), emissivitytotal =0.78 (oxidized iron surface), density of iron = 7.2 mg/m 3, specific heat capacity of iron = 0.50 kJ/kgK. How long will it take to heat the ingot to 600K, it may be assumed that the furnace is large compared with the ingot, and that the ingot is always at uniform temperature throughout its volume. convection effects are negligible. 200s distance between two large parallel plates (gray body) = 75mm, emissivity 1 = 0.8 @ 350K, emissivity 2 = 0.4 @ 300K. Calculate the net rate of heat exchange by radiation per square meter taking the StefanBoltzmann constant as 5.67x10E-8 W/m 2-K. 143.7 W/m2 emissivity of refractory material = 0.40 @ 1500K, emissivity of refractory material = 0.43 @ 1420K, T = 1500K (black furnace wall). What is the rate of gain of heat by radiation per unit area.. 24.3kW/m2 flow rate gas = 2.5 kg/m 2-s, Re = 20, 000, specific heat of gas @ constant  pressure = 1.67 kJ/kg-K. What will be the heat transfer coefficient be. h=13.4 W/m2-K heat is transferred from one fluid to a second fluid across a heat transfer surface. film coefficients for two fluids = 1.0 and 1.5kW/m 2-K, thickness metal = 6mm, thermal conductivity metal = 20 W/m-K, scale coefficient = 850 W/m 2-K. What is the overall heat transfer coefficient.. 317.5W/m2 K or 0.318 kW/m2-K in a shell-and-tube type of heat exchanger with horizontal tubes 25mm external diameter and 22mm internal diameter, benzene is condensed on the outside of the tubes by means of water flowing through the tubes, rate = 0.03m 3/s, Twater enter = 290K, T water leaves = 300K, heat transfer coefficient = 850W/m2-K. What total length of tubing will be required. 526m internal diameter smooth tube in a condenser = 25mm, length tube = 10 m, pressure drop over the length of the tube = 2x10E4 N/m 2, coefficient for the condensing vapor = 15,000 W/m 2-K, latent heat of vaporization = 800 kJ/kg. If vapor at a temperature of 353K is condensing on the outside of the tube and the temperature of the cooling water rises from 293K at inlet to 333K at outlet, what is the value of the overall heat transfer coefficient based on the inside area of the tube. what is the film coefficient for the water. what is the rate of condensation of vapor. U=6.57 kW/m2; hi=11.68 kW/m2-K;0.235 kg/s internal diameter spherical insulated vessel = 2m, *vessels are well lagged on the outside, thermal conductivity = 0.07 W/m-K, latent heat of vaporization of oxygen = 215kJ/kg, boiling point oxygen = 90K, density pf liquid oxygen = 1140 kg/m 3, atmospheric temperature=288K, heat transfer coefficient from the outside surface of the lagging surface to atmosphere = 4.5 W/m 2-K.. What thickness of magnesia la gging must  be used so that no more than 1% of the liquid oxygen evaporates during a journey of 10ks (2.78h) if the vessel is initially 80% full. 0.25m internal diameter steam pipe = 150mm, T steam = 444K *lagged with 50mm of 85% magnesia. What will be the heat loss to the air at 294K. 132 W/m; 90% by the addition of 50mm of lagging liquid is heated in a vessel by means of steam which is supplied to an internal coil in the vessel, mass of liquid in the vessel = 1000kg, *it takes half an hour to heat the contents from 293 to 368K if the coil is supplies with steam at 373K. the process is modified so that the liquid at 293K is continuously fed to the vessel at the rate of 0.28 kg/s. the total contents of the vessel are always being maintained at 1000kg. What is the

equilibrium temperature which the contents of the vessel will reach, if heat losses to the surroundings are neglected and the overall heat transfer coefficient remains constant. T=360.7K mass flow rate air = 0.9kg/s , T 1 = 283K, T 2 = 366K, T flue gas entering  = 700K, Tflue gas leaving  = 366K, free flow mass velocity flue gas = 10 kg/m 2s, inner and outer diameter pipe = 12mm, specific heat capacity of air and flue gases = 1.0 kJ/kg-K, *air passing through the pipes of a bank consisting of 20 rows with 20 pipes in each row. the arrangement is in-line with center to center spacing, in both directions, equal to twice the pipe diameter. Neglecting gas radiation, how long should the pipes be. Values of k and which may be used for both air and flue gases, are given below. 1.73m mass flow rate crude oil = 37.5 kg/s, T 1 = 295K, T 2 = 330K, mass flow rate bottom product = 29.6 kg/s, T 1 = 420K, T2 = 380K, shell diameter = 0.60m (tubular exchanger), having one pass on the shell side and two  passes on the tube side., number of tubes = 324, outside diameter = 19mm, wall = 2.1mm, length = 3.65m, square pitch = 25mm *supported  by baffles with a 25% cut, spaced at 230mm intervals. Would this exchanger be suitable. 0.234m2-K/kW mass of pure iso-butane = 7.5 kg/s , T = 331.7K (condensed temperature), Tinlet water   = 301K, outside diameter tube = 19mm, wall= 1.6mm, triangular pitch = 25mm, scale resistance = 0.0005m 2-K/W. Determine the number and arrangement of the tubes in the shell. 8.5% Order of reaction = 2 nd order; diffusivity of gas = 10E-8 m 2/s; rate of absorption at the interface = 4x10E-6 kmol/m2-s. In a continuous steady state reactor, a slightly soluble gas is absorbed into a liquid in which it dissolves and reacts, the gas concentration in the liquid falls to one half of its value in the liquid over a distance of 1mm, calculate the reaction rate constant on the assumption that the liquid is semi-finite in extent and that mass transfer resistance in the gas phase is negligible. 212 m3 /kmol-s Outside diameter pipe = 50mm; T steam = 413K; Coefficient of heat transfer (from its outer surface to the surroundings) = 10 W/m 2.K @ 288K. What is the heat loss per unit length. Q = 196W/m. It is desired to add lagging of thermal conductivity 0.03 W/m-K as a thick layer to the outside of the pipe in order to cut heat losses by 90%. If the heat transfer from the outside surface of the lagging is 5 W/m 2-K, what is the thickness of lagging. x=52.5mm outside diameter unlagged horizontal pipe = 50mm. Calculate the total heat loss by radiation and convection from unlagged horizontal steam  pipe at 415K to air at 290K. 163.7 W/m; 344.7 W/m outside temperature = 293K, thermal conductivity of lagging D = 0.05 W/m-K, coefficient for heat loss by radiation and convection from outside surface vessel = 10 W/m2-K, outside area of vessel = 8m, coil area = 0.2 m2, overall heat transfer coefficient for steam coil=300 W/m 2K. The contents of a reaction vessel are heated by means of steam at 393K supplied to a heating coil which is totally immersed in the liquid. When the vessel has a layer of lagging 50mm thick on its outer surfaces, it takes one hour to heat the liquid from 293 to 373K. How long will it take if the thickness of lagging is doubled. 3147s(0.87H)  pipe diameter=50mm (covered with two concentric layers of lagging), thickness pipe wall = 3mm, inner layer thickness = 25mm, thermal conductivity inner layer = 0.08 W/m-K, outer layer thickness = 40mm, thermal conductivity outer layer = 0.04 W/m-K. What is the rate of heat loss per meter length of pipe if the temperature inside the pipe is 550K and the outside surface temperature is 330K. 62.7 W/m t = 100s; diffusivity of CO 2 in ethanol = 4x10E-9 m 2/s. A deep pool of ethanol is suddenly exposed to an atmosphere consisting of pure carbon dioxide and unsteady state mass transfer, governed by Fick’s law, what  proportion of the absorbed carbon dioxide will have accumulated in 1mm thick layer of ethanol closest to the surface. 0.83 or 83% t =1800s (0.5h) to heat a tank of liquid using steam supplied to an immersed coil; T1 = 293K; T2 = 323K; Tsteam = 383K *the overall heat transfer coefficient from the steam coil to the tank is 10 times the

coefficient from the tank to surroundings at a temperature of 293K. How long will it take when the steam temperature is raised to 393K. 1578s (0.44h) T distillation column = 350K; P distillation column = 500 mmHg; mol A (more volatile) = 0.7 (at the interface with the liquid) = 0.5 (in the  bulk of the vapor); diffusivity in the vapor mixture = 2x10E-5 m2/s *the molar latent heat of the more volatile component is 1.5 times that of the less volatile *the resistance to mass transfer in the vapor may be considered to lie in a stagnant film of thickness 0.5mm at the interface. R = 8314 J/kmol-K. Calculate the mass transfer rates kmol/m 2-s of the two components.  X a  = 0.598. Calculate the mol fractions and concentration gradients of the two components at the midpoint of the film. Assume that the ideal gas law is applicable. 9.16 kmol/m4 T packed column = 295K; P = atmospheric ; [ammonia-air mixture] initial = 10%; [ammonia-air mixture] final = 0.1 % after scrubbing with water;  partial pressure ammonia = 660 N/m 2, at some intermediate point where the ammonia concentration is reduced to 5%; transfer rate = 10E-3 kmol/m2.s. If the whole of the resistance to mass transfer may be regarded as lying within a thin laminar film on the gas side of the gasliquid interface, derive from first principles an expression for the rate of absorption at any position in the column. 0.24 cm2 /s. What is the thickness of the hypothetical gas film if the diffusivity af ammonia in air is 0.24 cm 2/s. 0.043 mm T1 air  = 289K; T 2 air  = 313K *warming the air by passing it through a number of parallel metal tubes; inner diameter tubes = 50mm @ 373K;  pressure drop = not exceed 250 N/m2; density air @ 301K = 1.19 kg/m 3; k (convection) = 45, 62, 77 W/m 2-K; velocity @ 301K = 20,24,30 m/s. How long should the individual tubes be.. 1.95 the radiation received by the earth’s surface on a clear day with the sun overhead is 1kW/m 2 and an additional 0.3kW/m 2 , approximate radius earth = 700, 000km, distance between sun and earth = 150, 000, 000km. The temperature of the sun, the sun may be assumed to behave as black  body. 5710K thermal conductivity brick=1.0 W/m-K, thickness brick = 230mm, thermal conductivity plaster = 0.4W/m-K, thickness plaster = 10mm. If a temperature difference of 30K is maintained between the two outer faces, what is the heat flow per unit area of wall. 129W thermal diffusivity, DH = 0.0042 cm 2/s, thickness ID = 0.45m, T initial =290K, T2 = 470K , if the near face is suddenly raised to a temperature of 870K and maintained at that temperature. Assume that all the heat flow is perpendicular to the faces of the wall and that the distant face is  perfectly insulated, calculate the time taken for the distant face of a brick wall. t=0.120 Ms (33.5h) thickness firebrick furnace = 0.2m, T = 1573K (inside furnace wall), T =293K (ambient air adjacent to the furnace exterior), ho =3.0T E 0.25 W/m2-K (natural convection heat transfer coefficient at the exterior surface), thermal conductivity of firebrick = 1.5 W/m-K, thermal conductivity insulating brick = 0.4 W/m-K. The heat loss through a firebrick furnace wall is to be reduced by addition of a layer of insu lating  brick to the outside. What is the thickness of insulating brick necessary to reduce the heat loss to 400 W/m 2. x=1.18m Tsteam reaction vessel = 393K, area of steam coil = 2.5 m 2, area external surface = 40 m 2. overall heat transfer coefficient from the coil to the liquid in the vessel = 400 W/m 2-K. It takes 1800s to heat the contents from 293 to 373K when the outside temperature is 293K. When the outside and initial temperatures are 278K, it takes 2700s to heat the contents to 373K, show that the overall coefficient for transfer from the vessel to the surroundings is about 5W/m 2-K. 5 W/m2-K Twater   = 293K, length coil = 6.1m, internal diameter pipe = 25mm, thermal conductivity of the pipe wall = 20 W/m-K, wall thickness = 3.2mm, Tsteam = 373K, film coefficient = 8 kW/m 2-K, water velocity in  pipe = 1 m/s, T outlet = 309K. What will the outlet temperature be if the velocity is increased to 1.3 m/s, if the coefficient of heat transfer to the

water in the tube is proportional to the velocity raised to the 0.8 power.  K=976; T=307.7K Velocity air = 12.2 m/s; T air = 66 K; densit y air @ 310K = 1.14 kg/m3;; What will be the c orresponding pressure drop for a pipe temperature of 420K and an air temperature of 310K. 101.8 (N/m 2 )/m velocity air thru pipe = 12 m/s, inside diameter = 25mm, k (convection) = 60 W/m2-K. Neglecting the effects of temperature variation, estimate the pressure drop per meter length of pipe. 115.2 N/m2 per meter velocity water = 1.2 m/s (through series of 25mm diameter tubes 5m long maintained at 320K), T inlet = 290K. At what temperature would it leave. 306.4K; 306.06K volume jacketed reaction vessel = 0.25 m3, density liquid inside vessel = 900 kg/m3, specific heat = 3.3 kJ/kg-K, *the contents of the tank are agitated by a stirrer rotating at 3 Hz, heat transfer area =2.5 m 2, Tsteam = 380K, outside film heat transfer coefficient = 1.7 kW/m 2, tank wall = 10mm, thermal conductivity tank wall = 6.0 W/m-K, inside film coefficient = 1.1kW/m2-K, for a stirrer speed of 1.5Hz and proportional to the two-thirds power of the speed of rotation. Neglecting heat losses and the heat capacity of the tank, how long will it take to raise the temperature of the liquid from 295 to 375K. 2381s (40min) volume liquid = 0.1 m 3. specific heat capacity = 3kJ/kg-K, density = 950 kg/m3, heat transfer area = 1m2, Tsteam supplied = 383K, overall heat transfer coefficient in coil = 2000 W/m 2-K, heat transfer coefficient to surroundings = 311.8K. How long will it take to heat the liquid from 293K to 368K, if the tank, of external area 20m 2 is losing heat to the surroundings at 293K. To what temperature will the system fall i n 1800s is the steam is turned off.. 1559 s(0.43h); 311.8K volume liquid = 0.18m 3, density liquid = 900kg/m 3, specific heat liquid = 2.1kJ/kg-K, T 1  = 293K, T 2  = 377K, Tsteam feed= 383K, overall heat transfer coefficient = (constant) 0.5 kW/m 2-K, external surface vessel = 2.5m, coefficient for heat transfer to the surroundings = 5W/m 2-K @ 293K, how long will it take to heat the liquid , 2085s (0.58h). The batch system of heating is to be replaced by a continuous countercurrent heat exchanger in which the heating medium is a liquid entering at 388K and leaving at 333K. If the heat transfer coefficient is 250W/m 2-K, what heat exchange area is required. Heat losses may be neglected. 2.44m2 x firebrick = 225mm, k=1.4 W/m-K, x insulating brick = 120mm, k=0.2 W/m-K, x building brick = 225mm, k=0.7 W/m-K, T inside  = 1200K, Toutside = 330K. Find the heat loss per unit area and the temperature at the junction of the firebrick and insulating brick. 803.3 W/m2; 589K

Estimate the boiling point… 15-mol% NaCl, 10-mol%MgCl2 and 18mol% CaCl2… 140o F  For the same duty and heat transfer area, the feedforward flow evaporator is ___ compared to backward feed… less efficient  If the OHTC of the evap. of prob 10 is 200 BTU/hr-ft2- oF… the heating area in ft 2 … 38 If the sol’n to be evaporated tends t o strongly scale… forced circulation In a country where capital is scarce and energy cost is low… single effect evaporator In evaporation operation, the valuable product is… thick liquor  Referring to prob 13, economy of evap… 0.80 Referring to prob 13, estimated heating surface in m 2… 0.70 Referring to prob. 21, heat transfer area of the 1 st? 66.1 Referring to prob. 21, heat transfer area of the 2 nd? 68.8 Sat. steam at 25psia enters a surface… the required cooling water in lb/hr? 4130 The BPR of 30%wt NaCl at 1 atm… 20o F  The concentration of glycerine from water solution… evaporation The temp. driving force in an evap. is determined as difference between condensing steam and… boiling point of the sol’n Water enters the bottom of a vertical evaporator tube 20ft long… fraction of the liquid water entering the bottom? 0.0217  When the pressure of the evaporator chamber is decreased, the boiling  point inside will decrease Which of the two evaporator…needs fluid motive devices to transfer solutions… backward feed 

A 10%wt NaOH sol’n at 80 oF… the heating surface required in ft2… 91 A 7wt% NaOH sol’n enters an evap. at 98 oF… the number of BTU required to evap. 1.5lb H 2O… 1670 BTU  A certain evap. is  boiling a solution… after 4hrs and 10min… coefficient at the start of operation… 652 A double effect evap. is heated w/ st eam at 250 oF. The 2 nd effect is under vacuum… Boiling Point in 1 st… 208o F  A heat transfer device that is normally used to liquefy vapors… condenser  A liquor containing 15% solids is concentrated to 55%. The feed rate is 2.5kg/s… evaporation in 1 st in kg/min? 52.5 A sol’n of organic colloids is concentrated from 20 to 65%... the steam consumption in kg/hr… 11,400 A triple effect evap. is supplied with 250 oF sat. steam… the area of the first effect in ft2… 3300

A P&FFP contains 24 frames, each 1 in thick … the capacity of the press is? 936 ft 3 /day A P&FFP is used to filter a certain sludge for 2hrs at constant pressure. Time of washing is? 96 mins A P&FFP is used to filt er a compressible sludge (s=0.45) at 50 psifor 2 hrs… the washing time is? 127 min A P&FFP with 10 frames is used to filter a slurry at a constant  pressure… the time to produce 400lb of filtrate, assuming Rm=0 is? 7.5 min A rotary drum filter with 35% of its filtering area submerged in the slurry turns at 0.5 rpm… estimated area of the filter cloth in m 2? 1.6  A rotary vacuum filter w/ negligible filter medium resistance delivers 125 ft 3 of filtrate per minute… the volume of filtrate delivered per hour is? 10,620 ft 3

A small leaf filter is run at constant rate… the filtrate collected in 20 minutes is? 41.5 gallons A standard leaf filter gives 20 ft 3 of filtrate in 2 hrs of filt ration time per cycle… the capacity of leaf filter in ft 3/hr is? 4.4 During filtration of slurry, the filtration will st art to fall once the pressure … becomes constant  During filtration on a rotary filter, the precipitate is continuously removed by scrapper in order to … keep the filter clean For a non-washing constant pressure filtration where the resistance of the medium is negligible, max. capacity is attained when the filtration time is… equal  If a duplicate pump were installed in parallel with the present pump in  prob 15, the percent reduction in filtration time is? 7.7%

A multiple contact extraction system is to treat 1.25 tons (2,500 lbs)/hr of dry black ash containing 40% Na 2CO3… the number of ideal stage req’d is? 2 stages a slurry of flaked soybeans weighing 100kg contains 75kg inert solids and 25k g solution… composition of underflow leaving the extraction? 0.8 A unit op. in which a soluble component is removed from an inert solid  by solvent which dissolves the soluble matter is known as… leaching  Agitation in liquid influences the rate of extraction. Agitation of solvent is important because… it increases the transfer material  …

Coconut oil is to be produced from dry copra in two stages… dry copra cake contains 20% residual oil… number of ideal stages required is? 5  stages Composition of salt in weight percent in the final underflow is? 0.89%

If only ½ of the original filtrate volume of prob 15 were to be collected, the new filtration is? 24.4 min In a constant rate filtration test, the pressure rises from 4 to 45 psi in 10 mins collecting 3 ft 3 of filtrate… the equivalent resistance in ft3 is? 0.293 In a Plate&Frame filter press, the rate of filtration is directly  proportional to… cross section of the filter press In filtration operation, the flow rate is directly proportional to …  pressure applied  In filtration, the coarser the filtration medium… the longer  In P&FFP, the rate of washing is equal to? ¼ In the filtration of Al(OH) 3, the following data were obtained: the pump is operated at 50 psia… the total filtration time is? 38.3 mins Referring to prob. 9, if the drum has diameter of 1.0m, the width in cm? 51 The capacity of a rotary vacuum filter will change by a factor of 1.1 if the submerged area is increased by 20%. The eq’n: V f 2=22.5x103(θf  +0.11)… the total cycle time for maximum filtrate output during 24 hr is? 12 hrs

Extraction of coffee from its seed is done by… leaching  In a salt recovery plant, rock salt is being leached to produce industrial salt… inerts=70%, soluble salts=25%, moisture=5%... quantity of salts recovered in MT/day is? 12.1 In ideal leaching conditions, the tie slant to the right indicating that the solute is more highly concentrated in the underflow because… equilibrium solubility/incomplete leaching  In leaching, the particle size influences the extraction rate, the smaller the size… greater interfacial area and smaller the distance (both a and b) Leaching of sugar from sugar beets is done using… hot water   Number of extraction cells req’d if each ton of dry pulp retains 3 tons of water? 17  Powdered limestone (CaCO 3) containing 10,000ppm NaOH… the  NaOH content of the washed and dried limestone in ppm is? 0.8 Raw gypsum from a fertilizer plant is being leached out of its salt (NaCl)… raw gypsum = 10MT/day, Salt content=1%wt, water feed rate=90m3/day… the % of the salt removed is? 99.9%

The equation that is applied to describe the flowof a fluid through a  porous medium… Kozeny-Karman Eqn.

Roasted copper ore containing the copper as CuSO 4 is to be extracted in a countercurrent stage extractor… 10 tons gangue, 1.2 tons CuSO 4, 0.5 tons of water… the number of stages req’d is? 10

The filter fabric (or filter medium) to use in which strong breaking tenacity and strong abrasion resistance are req’d is? Nylon

Stage efficiency in a leaching process depends on the… both a and b

The operation by which solids are separated from liquids due to difference in densities… sedimentation

A countercurrent multiple contact extraction system is to t reat 50 tons/hr of wet sliced sugar beets… water=0.48, pulp=0.40, sugar=0.12… number of extraction cells req’d if each ton of dry pulp retains 3  tons of sol’n? 16 

Tea percolation employs? Leaching  The major problem in leaching is to promote diffusion of the solute out of the solidand into the liquid. The most effective way is? to use countercurrent operation The rate of leaching increases with increasing… temperature The resulting salt content in the overflow in weight % is? 0.112

The temp. also affects the rate of extraction. In most cases, the solubility of the material which is being extracted will increase with temp. to? Both a and b There are two underflow-overflow leaching conditions namely ideal a nd non-ideal. Ideal leaching condition exist if? All of these Tung meal containing 55% oil is to be extracted at a rate of 4,000 kg/hr using n-hexane… theoretical number of stages is? 4 stages Which of the following operations does not involve leaching? Removing nicotine from water sol’n by kerosene

The topic of drying and driers is taken up as part of Unit Operations in ChE since… the quality of the solid product is affected by moisture The value of constant drying rate, R c, varies directly with the quantity… therefore, increasing the humidity… decreases the rate of drying This is the moisture in the solid that exerts the equilibrium vapor  pressure of the liquid at the prevailing conditions… unbound moisture This type of drier is used for drying pasty materials such as wet filter cakes and lumpy soils… tray drier  Unbound moisture in granular and porous solid moves through the interstices of a solid by a mechanism involving… moisture diffusivity

A wet material having a critical moisture content of 15% (d.b.) and an equil. Moisture content of 3% (d.b.)… 4.9 hours Drum driers are used for drying…  pastes

under normal operating conditions, when a solid material to be dried is  placed i nside a batch dryer, the ma terial i s usually subjected… under constant drying conditions

Given a solid material containing 120% moisture on a dry basis, the equivalent moisture in % moisture is… 54.5%

Wet solids are to be dried from 40% to 10% in 5 hours under constant drying conditions… The time needed to dry 15% to 5% under same conditions… 1.6 hours

If there’s no heat transfer by radiation and conduction from adjoining surfaces, the temp. of the solid subjected… nearly equal to the wet bulb temp of drying medium

When a porous solid is subjected to constant drying conditions starting w/ bound moisture, the removal of moisture from the solid is initiated  by pendular state followed by funicular state… false

In the absence of radiation and heat conduction through the solid during the constant drying rate period… wet bulb temp. of the gas

when a solid material is being dried in a continuous tunnel drier under low temperature drying, the mechanism is considered to be…  simultaneous mass and heat transfer

In the constant rate period, the rate of drying is established by… a balance of heat requirements… In the drying at the falling rate period, the rate at which moisture is removed from the solid material… decreases with time It is a unit operations which involves the mass transfer of soluble materials from the liquid phase to gaseous phase… desorption It is the rate of drying under constant drying conditions with air at 140 oF and absolute humidity of 0.03lb water/lb dry air… R=0.5 -e-60X lb H2O/hr-ft2… equilibrium moisture content of material… 0.01155 the choice of equipment to be used for drying of solids can be classi fied according… all of these

When a solid material is said to be “dry”, it means… the solid still contains very small amount of moisture when a wet granular solid material c ontained in a metal tray w/ insulated edges… the heat transfer mechanism involved in the drying opera tion is… by convection and radiation When a wet solid is brought in contact with air, the solids tends to lose moisture if the humidity in air is… lower than the humidity corresponding to the moisture cont. of the solid  When drying a banana chips under the sun, the rate of drying is faster on a… hot and windy day When the solid is non porous… liquid diffusion

The critical moisture content of a solid depends on the drying history and the thickness of the material… true the equipment is operated immediately under unsteady state conditions… batch drying The estimated mass transfer coefficient for the above drying conditions is… 50lb H 2O/hr-ft 2- Δ H  The first point of the falling rate period corresponds to… critical moisture drying the free moisture content of the solids does not depend upon … the nature by which heat is supplied The portion of water in the wet solid that cannot removed by the air in direct contact with the solid is called… equilibrium moisture content

A 25 mm ID wetted wall column is used to absorb dilute SO 2 in air at 293 K with a velocity of 2.2 m/s. i f D v= 0.455 ft 2/hr, the gas film coeff… 0.0373 A wetted wall column is usually preffered over a packed column to determine mass transfer coefficient experimentally because for a wetted wall column The mass transfer area Assuming that the penetration theory applies in an interfacial mass transfer contact, the liquid phase mass transfer coeff will increase by a factor…. 2 Co- current gas- liquid up flow contacting device is highly characterized  by dispense bubble flow regime

Flooding condition is the only consideration that dictates the minimum column diameter that can be used for a specified gas absorption in a  packed column False For an absorber (mass transfer from gas gas to liquid) the operating line always lies above the equilibrium solubility curve For moderately soluble gas with relatively little interaction between the gas and liquid molecules, the law which applies most to establish equilibrium relationship is Henry’s Law Given the individual mass transfer coeff and equilibrium eqn at 25 0C , k xa=60, k ya=15 mol/hr. ft 3mole fraction and x*=0.3226y…. 8.45 if the solute free gas flow rate is 500 kg-mole/hr of 0.10 mole ratio of solute entering the plate absorber at 1 atm, what is the minimum water.. 103 In a gas absorption column, the pressure of the lean gas is expected to  be lower than In a gas absorption packed tower, the most economical gas velocity is considered to be about half In a gas absorption tower, mass transfer occurs primarily  from the gas  phase to the liquid phase In a stripping or desorption operation, the equilibrium curve is above the operating line In an absorption tower packings are placed inside to  provide a bigger mass transfer area In gas absorption, packings are used to increase the area of contact between the gas and the liquid In gas absorption, the use of a liquid rate far above the minimum value will result in  fewer number of plates In gas absorption, when the conditions at the bottom of the tower are fixed and the gas flow rate is given, the limit ing flow rate based on equil conditions that will require infinitely tall tower is maximum liquid flow rate In mass transfer, a transfer unit means that the concentration range is equal to the average driving force In packed columns, the pressure drop for irrigated packings is always greater than the pressure drop for dry packings because the flow area of dry packing is greater In the case of a straight or concave downward operating line and a straight or concave upward equilibrium line, the minimum li quid rate is that at which the operating line just touches the equil line at the bottom of the tower  In the choice of a solvent for gas absorption, one of the properties to be considered is solvent should have a low vapour pressure It has been determined that the equivalent HTU and NTU of a packed absorption tower are 0.85 ft and 15 respectively. If the same …. 1.275 It is a unit operation which involves the mass transfer of soluble materials from the solid phase to the liquid phase leaching  It is not very necessary to correct the rate eqn for the phase drift encountered during gas absorption, since the height calculated will be  slightly over designed anyway Pressure drop is one of the most important parameters in the design of two phase concurrent bed because all of these The analogy between mass and heat transfer is complete when no convective flus or phase drift is involved The interfacial concentration yl in a gas absorber corresponding to y= 0.05 mole fraction is _ mole fraction. The slope of the operating line is 1.3.. 0.02 The mass transfer rate of a material from one phase to another across an interface is increased by increasing The mechanism of mass transfer in a gas absorber is best described by the Two-Film Theory The method of separating a particular gaseous component from a mixture of gases due to their differences i n solubility I a liquid phase is absorption

The mole fraction of solute entering a gas absorber is 0.25. if the  percentage recovery is 75% , then the mole fraction of the solute leaving…. 0.0769 The overall height of a transfer unit based on the gas phase will equal the gas phase individual HTU, H y when the liquid phase resistance is very small compared with the gas phase The pressure drop along a packed tower is directly proportional to the  square of the mass flow rate The rate eqn in terms of the gas phase mass transfer coefficient is used in design calculations instead of that in terms of the liquid phase when the controlling resistance is that of the gas phase The total weight of a 13 mm ceramic raschig rings that can be contained in a cylindrical gas absorption tower 5m high and 0.55m in diamete r …. 1045 When dilute sol’ns are involved in gas absorption, one of thw following is not applicable   =

  

When the gas flow rate induces flooding in a packed column gas absorber, this is best remedied…. increasing the diameter of the column When the liquid flow rate is fixed and the composition of the liquid and gas at the bottom of the absorption tower are fixed, t he limiting flow rate to give ifinitely tall tower becomes the minimum flow rate of the vapor When the two film theory is applied to gas absorption, the overall resistance can be expressed in terms…. the slope of the equil curve near the tie line is linear

A sling psychrometer is whirled on a fast spin when measuring the wet  bulb temperature of ambient air to minimize the effect of radiation on the temperature reading Air conditioning involves dehumidification Air supplied at the rate of 1200 cfm to a refrigerated coil, has a relat ive humidity of 20% and dry bulb temp of 150 0F. The mass flow rate of dry air entering per minute is 74.1 An air-carbon tertrachloride-vapor mixture at 100 0F dry bulb and 60 0F wet bulb is heated until the temperature reaches 180 0F. The final  percentage relative humidity is about 5% An indication of the moisture content of ambient air is its wet bulb temperature Besides measuring the dry bulb and wet bulb temperature in determining the humidity of air, another method may be used. This is by measuring the dew point of the air  Fogging is a result of a condition whereby the gas becomes  supersaturated with vapor For a cooling tower with a circulating water flow of 5000 gpm, an inlet and outlet water temperature of 100 0F and 80 0F, respectively and 0.5% drift loss, the estimated make-up water is 110 gpm For a dehumidifier, the slope of the tie line is 2.5 for a liquid to gas ratio of 1.0. air enters the dehumidifier at 80 0F db and 78 0F wb while water leaves at 760F. Estimate the interfacial temperature at a point …. 63.50 F For air-benzene vapor mixture at 1 atm, the dry bulb temperature is 1000F and wet bulb temperature of 90 0F. the absolute humidity at this condition is 0.52 For an air flow rate of 5000 lb/hr and a water flow rate of 7500 lb/hr, the temperature of the cold water is 80 0F using air with temperature of 90 0F dry bulb and 70 0F wet bulb. The estimated…. 880 F  For dehumidification, when the top liquid flow rate is fixed and the top conditions of water temperature and air enthalpy.. maximum air flow rate For the air-water vapor system, the Lewis relation h y/k yc3 takes a value of essentially equal to unity Given a counter flow induced-draft cooling tower with the following operating data: hot water temperature= 115 0F, cooling range= 30 0F, wet

 bulb temperature= 70 0F, water flow rate= 500 gal/min. Assuming…. 7 hp If 100 lb of dry air at 50 0F db and 50 0F wb is mixed with 300 lb of dry air at 1100F db and 80 0F wb, the resulting mixture will have a dry bulb.. 95 0 F  If the air flow rate is 1000 lb/hr, the maximum water rate needed for the tower in the previous problem i s about 3400 lb/hr  If the mass transfer coefficient, K Ga= 230 lbs water/hr-ft3-atm, then the MTC in lb water/hr-ft 3-absolute humidity is 370.6  If the partial pressure of the vapour in a gas- vapour mixture is, for any reason, less than the equil vapor pressure of the liquid at the same temperature, the mixture is unsaturated If the temperature of t he air entering the t ower of the previous problem (problem 24) is 100 0F, the exit temperature of the air is estimated to be (use Mickley’s graphical method) 1050 F  In adiabatic humidification, it is possible t o maintain the temperature of water constant since the system can be well insulated from the  surroundings In an air water contact equipment, the individual gas phase mass transfer coefficient is equal to the over-all mass transfer coefficient since the mass transfer resistance in the liquid phase is small In an air-water contact operation, when the temperature and humidity of the air both decrease the process is dehumidification In dehumidification, where the Lewis number is equal to one, the operating line on the gas-enthalpy-liquid temperature graph is above the equilibrium curve In order for the gas to be dehumidified, as in the water vapor air mixture, the humidity of the gas must be  greater than the gas-liquid interface In terms of heat transfer, the use of a cooling tower is said to be more efficient and more economical compared to an ordinary heat exchanger since temperature profiles of air and water can cross each other Moist air is found to contain 8.1 grams of water vapor per cubic foot at a temperature of 30 0C. Calculate the temp to which it must be heated…57 0C  The air in the room is at 26.7 0C and a pressure of 101.32 kPa and contains water vapor with a partial pressure Pa=2.76kPa. calculate the %.... 78.3% The dew point of air indicates the temperature at which its water content will start to condense The enthalpy entering and leaving a cooling tower is 52.0 and 75 BTU/lb, respectively. If the inlet and outlet water temperature are 1200F and 100 0F, respectively, the estimated overall…. 0.76  The enthalpy transfer eqn based on Merkel’s procedure of determining the volume of a cooling tower is a convenient way of eliminating the determination of interfacial temperature and humidity The enthalpy transfer equation as proposed by Merkel is applicable to air-water system only because the ratio of h e convective heat transfer coefficient and the mass transfer coefficient, k yMB is equal to the humid heat  The height to diameter ratio of a cooling tower is much less compared to that of a gas absorber because the gas flow rate is larger The process which illustrates the principles of adiabatic humidification is spray chamber  The ratio between partial pressure of water vapour in air and the vapor  pressure of the water at the air temperature multiplied by 100 is  percentage relative humidity The relative humidity of air at a given temperature is the the ratio of the  partial pressure of the water-vapor and the vapor pressure of water The relative humidity of unsaturated air-water vapor mixture is always  greater than The temperature at which the moisture in humid air exerts a partial  pressure equal to its vapor pressure is called the dew point 

The tons refrigeration needed to supply air in a room 20 ft by 20 ft by 10 ft charged every 5 min at 70 0F dry bulb and 65 0F wet bulb by cooling outside air at 120 0F db and 100 0wb is 14.3 The wet bulb temperature of the resulting mixture for the mixed air for the previous problem is 750 F  This is a steady-state temperature reached by a small amount of liquid evaporating into a large amount of unsaturated vapor-gas mixture wetbulb temperature This is the temperature at which a vapour gas mixture becomes saturated when cooled at constant humidity. dew point temperature This is the temperature of a vapour-gas mixture as ordinarily determined  by immersion of a thermometer in the mixture dry bulb temperature Which of the following processes is followed by unsaturated air (with dry bulb temperature 12 0C and relative humidity 47%) passing through water spray washer (temp of water being constant at 40 0C). both heating and humid  Without adding or removing any water vapor, a sample of air experiencing an increase in temperature will have lower relative humidity

1200 lb of barium nitrate is dissolved in sufficient water to form a saturated solution at 900C. Assuming that 5% of the weight of the original solution is lost through evaporation, calculate the crop of crystals obtained.. 962.4lbs A batch of 1000 kg of KCl is dissolved in sufficient water to make a saturated solution at 363K, where the solubility is 35% wt \k\cl in water. The solution is cooled to 293K at which temperature the solubility is 25.4% wt… 400g  A diluent is added to the mixture, the solution is then directly or indirectly cooled and/or solvent is evaporated to effect crystallization  solution crystallization A plant produces 30,000 MT of anhydrous sodium sulphate annually by crystallizing process sulphate brine at 0 0C. Yields of 95% and 90% in the crystallization and calcination operations are obtained,…. 2387  A solution of magnesium sulphate containing 43g solids per 100g watter is to be fed to a vacuum crystallizes at 220 0F. The vacuum in the crystallizer corresponds to a water boiling temperature of 43 0C… 5235 lbs per hour  A solution of MgSO 4 at 2200F containing 43g of MgSO 4 per 100 g H 2O is fed to a cooling crystallizer operating at 50 0F. If the solution.. 3.71 tons/h A Swenson-Walker crystallizer is fed with a saturated solution of magnesium sulphate at 110 0F. The solution and its crystalline crop are cooled to 400F. The inlet solution contains 1 g of seed crystals per 100g of solution. The seeds are 80-mesh. Assuming ideal growth, the mesh size of the ..28 A Swenson-Walker crystallizer is to be used to produce 1 ton/hr of copperas crystals by cooling a saturated solution which enters the crystallizer at 1200F. The slurry leaving the crystallizer will be at 800C.. Compounds whose solubility increase with increasing temperature results in absorption of heat when the compound dissolves Cooling water required is.. 52 gpm Crystals of Na 2CO3-10H2O are dropped into a saturated solution of  Na2CO3 in water at 1000C. What percent of the Na 2CO3 in the Na 2CO3H2O is recovered in the precipitated solid? The precipitated solid is…. 25% During crystallization, formation of crystal can occur in __ solution only  supersaturated  Equilibrium in crystallization process is reached when the solution is  saturated  Glaubers salt is made by crystallization from a water solution at 20 0C. The aqueous solution at 20 0C contains 8.4% sodium sulfate. How many

grams is 1.077 so that when the residue solution after evaporation is cooled at 20 degrees Celsius… 801.52 How much CaCl 26H2O must be dissolve in 100 kg of water at 20 0C to form a saturated solution? The solubility of CaCl 2 at 200C is 6.7 gmol anhydrous salt (CaCl 2) per kg of water 535 kg  If an aqueous solution of 25% wt MgSO 4 at 140 0F is cooled to 30 0F, the mother liquor concentration will be _ %wt MgSO 4 18 In industrial crystallization from a solution, the two phase mixture of mother liquor and crystals of all sizes, which occupies the crystallizer and is withdrawn as product is called magma Most modern crystallizers fall in the category of__ units in which adiabatic evaporative cooling is used to create supersaturation Vacuum One ton of Na 2S2O3-5H2O is to be crystallized per hour by cooling a solution containing 56.5% sodium thiosulfate to 30 0C in a SwensonWalker crystallizer. Evaporation is negligible. The product is to be sized….1138.5 Referring to (previous problem), the type of crystals formed is  MgSO42H 2O The concentration difference between that of the supersaturated solution in which the crystal is growing and that of a solution in equilibrium with the crystal is called supersaturation The enthalpy of a 25% wt of MgSO 4 at 82.2 0C in BTU/lb solution is 40 The enthalpy of MgSO 4-7H2O at 26.67 0C in BTU/lb solution is -150 The enthalpy of saturated MgSO 4 at 1500F in BTU/lb solution is -25 The equation relating the solubility of the substance to its particle size is called Kelvin The formation of a new solid phase either on an inert particle in the solution or in the solution itself is called nucleation The heat of solution of hydroxybenzene in g-cal/gmol is -2,605 The heat of solution of saltpeter in kg-cal/gmol is -8.633 The latent heat evolved when solid forms from solution which varies with both temperature and concentration is called heat of crystallization The number of crystallizer units to be used is.. 7  The solubility of Epsom Salt in equilibrium with the saturated solution at 100C in g/100g water is 30.90 The solubility of sal ammoniac at 70 0C in g/100g water is 60.2 The solubility of soda ash at 30 0C in g/100g water is 38.3 The solubility of sodium bicarbonate in water is 9.6g/100g of water at 20 0C and 16.4g/100g of water at 60 0C. If a saturated solution of NaHCO 3 at 600C is cooled to 20 0C, the percentage of the dissolved salt that crystallizes. 41.5% This crystallizer uses the method of supersaturation by evaporation of solvent Oslo Which of the following solute may be crystallized by cooling without evaporation, evaporation without cooling or a combination of cooling and evaporation Sodium Nitrate

80g of F2 is reacted with 40g P 4 to form 90 g of product PF 3. A flue gas from a certain furnace burning a fuel of negligible nitrogen content is found by analysis to contain 12% CO 2, 7.5% O 2, and 80.5%  N2. Calculate the percent excess air. 54.6% A mixture of acetone vapor and nitrogen contains 14.8% acetone by volume. Calculate the relative saturation and the % saturation of the mixture at a temperature of 20 C and pressure of 745 mmHg. 59.7%, 52.9% A sample of lignite was found to contain 34.55% moisture, 22.93% FC, 7.2% ash, 1.2% S, and 0.57% N with a calorific value of 16.45 MJ/kg. Calculate percent net H. 0.52% Calculate the percentage conversion. 92% Determine the percentage yield. 79% Hydrogen in fuel that needs oxygen from air for it s combustion is known as. Net Hydrogen

In the combustion of solid fuels, what is the key component between the feed and the refuse? Ash In ultimate analysis, calculate percent H. 5.46% In ultimate analysis, calculate percent O. 39.52% It is normally used to det ermine the quality of combustion gases. Orsat  Analysis It is the portion of t he coal which when heated in the absence of air under  prescribed conditions is liberated as gases or vapour. Volatile matter  Pig iron is produced in a blast furnace from hematite ore containing 80% Fe2O3. The pig iron produced is 96% Fe. The slag contains 10% of iron  present in the ore. How many tons of pig iron is produced per 500 tons of ore? 272 The flue gas from the combustion of a hydrocarbon fuel has the following Orsat analysis: 5.66% CO 2, 2.43% CO, 6.4% O 2, and 85.4%  N2. The percent excess air supplied is. 30% This is the empirical relation which allows one to compute for the net hydrogen in a given solid fuel.  Dulong’s Formula Which of these is not a form of hydrogen present in solid fuels?  None of the above

A catalyst increases the rate of a chemical reaction by.  Lowering the activation energy of the reaction A certain temperature dependent reaction proceeds 10 times faster at 500 K than it does at 300 K. How much factor will it react at 1000 K than it does at 300 K. 56.23 times faster A gas decomposes at 900 C according to the reaction 2A → 2R  5 with a rate constant of 1000 cm 3/mol-s. Using pure A, the time it will take to react 74.25% of A in a constant volume batch reactor at 900 C and 1 atm in minutes is __. 7.43 A liquid phase double-replacement reaction between bromide cyanide (A) and methylamine takes place in a PFR at 10 C and 101 kPa. The reaction is first order with respect to each reactant, with K A  = 2.22 L/mol-s. If the residence time or space time is 4 sec, and the inlet concentration of each reactant is 0.1 mol/L. determine the concentration of bromine cyanide at the outlet of the reactor. 0.053mol/L A liquid polymerization of a certain monomer at constant temperature showed that after 34 minutes conversion is 20% when the initial concentration used is 0.04 mol/L. When the initial concentration used is 0.9 mol/L, conversion is 20% after 34 minutes. What is the specific rate constant for this reaction? 0.0066/min A substance A decomposes by first order kinetics. In a batch reactor, 70% A is converted in 10 min. How much longer would it take to reach 99.9% conversion? 57.4 min In a potential energy diagram, the difference between the potential energy of the products and the potential energy of the reactants is equal to the. Heat of reaction In steady-state backmix flow reactor, composition is not. Constant throughout the reactor The homogenous gas decomposition of phosphine 4PH (g) → P (g) → 6H (g) proceeds at 1200 F with first-order rate, r A= (10/hr) C A. What size of PFR operating at 1200 F and 4.6 atm can produce 80% conversion of a feed consisting of 2.75 lbmol phosphine per hour? 160ft 3 The irreversible reaction takes place in a CSTR under the following conditions. FTo = 40 mol/min, C ao = 2 mol/dm3. The feed is 40% A. K (400K) = 0.1/min and V = 600 dm 3. Calculate conversion of A. 0.87  What is the order of the reaction if the graph C vs t gives a straight line?  zero order  What is the reaction rate constant for the third order reaction? L2 /mol 2-s What plot generates a straight line for a zero order reaction? [A] vs time Which even must always occur for a chemical reaction to take place?  Effect collisions bet. reacting particles

A bed consists of uniform spherical particles of diameter 3 mm and density of 4200 kg/m 3. What will be the minimum fluidizing velocity in a liquid of viscosity 3 mPa-s and density of 1100 kg/m 3? 36.4 mm/s A centrifuge with a 20-in diameter bowl, 14-in deep operates at 1200 rpm giving a 2-in thick liquid layer when used with a sludge whose liquid has a specific gravity of 1.2 and a viscosity of 2.5 cp. The solid component of the sludge has a specific gravity of 1.7. If the cut size of the particles is 35 microns, what is the capacity of the centrifuge in gallons per minute? 843 The boiling temperature of ethylbenzene is 136 C. Estimate the enthalpy of vaporization of ethylbenzene at this temperature. 35KJ/mol  Oil flows under laminar conditions inside a steam heated copper pipe. The overall heat transfer coefficient is approximately. Equal to the heat transfer coefficient of the steam 200 mesh screens means. 200 openings/in 2 We must cool 2500 gallons per minute of water from 120 F to 80 F. A cooling tower at 70 F and 1 atm is to be designed to operate with entering air of 40% RH. How many cubic feet per minute of ent ering air must be supplied? 1.61x105cfm Estimate the terminal free settling velocity in air at 20 C if a dust sphere with a diameter of 1 micron and specific gravity of 2. 1.97x10-4 ft/s

Production of potassium, named after a place in US. Trona process Starch has the formula. ( C 6 H    10O5 )n Kraft process is a common name for, sulfite pulping  The name “rubber” was apparently given by ______, who first observed the ability of the material to “rub out” a pencil mark.  Joseph Priestly Produced by fermenting potatoes and then by distillation (Russia). Vodka In the Philippines, sulfur for sulfuric ac id manufacturing is sourced from  _______ industry. Paper  Production of wet-processed phosphoric acid which uses HCL to acidulate raw phosphate rock then an organic solvent is used to extract the phosphoric acid. Haifa Which of the following is a lso known as black diamond? Carbonado What is the other for blue gas? Water gas The gasification reaction represented by C + H 2O = CO + H 2, is an a/an.  Endothermic

A solution of sodium sulfate in water is saturate at a temperature of 40 C. Calculate the weight of crystals obtained by cooling 100 lb of this solution to a temperature of 5 C. 69.5% (or 69.82%) Calculate the percentage yield obtained by cooling 100 lb of this solution to a temperature of 5 C. 90% The distillation process involves. Heat and mass transfer  A mixture containing 60 mols of n-pentane and 40 mols n-heptane is subjected to differential distillation at 1 atm until 40 mols are distilled. Assuming the relative volatility is 8.0, what is the concentration of the distillate? 0.925 Moisture content at which the drying rate first begins to drop. Critical moisture content  Consider the frying operations with critical moisture content of 0.10 and an equilibrium moisture content of 0.005 and for a solid loading (db) of 50 kg/m2 with a constant drying rate of 5 kg/m 2-hr. The falling rate of drying is linear with moisture content. The drying time (hrs) required to reduce an initial moisture content of 25% to a final moisture content of 2% is ____. 3.25 If the air leaves the dryer 50% saturated and if the dryer operation is adiabatic, obtain with the use of the relative humidity chart the following: Dew point in F of fresh air. 59.6 Percent relative humidity of fresh air. 58% Humidity in lb water vapor per pound dry air of fresh air. 0.0109 An engineer designed an engine that has an efficiency of 25% and will absorb heat at a temperature of 267 C. Compute the temperature at the exhaust considering that this is an ideal engine. 132 C     

A Venturi meter is being used to determine the flow of soyabean oil at 65 C in a pipe. The particular pipe is 15 cm in diameter, which decreases to 6 cm in the throat of the Venturi. The differential pressure is measured as 14 cm of water. Estimate the volumetric flow rate of the soyabean oil. 0.17 m 3h-1 Estimate the mass flow rate of the soyabean oil. 153 kg h -1

Which of the following is an essential amino acid? Methionine There is DNA or RNA coated protein that ma y or may not be considered as living things. Virus Process in central dogma wherein DNA is replicated in the form of mRNA. Transcription The chemical messenger released by the endocrine gland into  bloodstream and transported there to reach its target cell is called  ________. Hormones What is the enzyme present in cheese? Rennin An enzyme catalyses a reaction at a velocity of 20 mol/min when the concentration of substrate [S] is 0.01 M. The K M for this substrate is 1x10 -5 M, assuming that Michaelis-Menten kinetics is followed. What will the reaction velocity be when the concentration of [S] is 1x10 -6 M? 1.82x10-6 mol/min These are mixtures of triglycerides containing high proportion of long chain, unsaturated fatty acids or short chain, saturated fatty acids. Oils The microorganism utilized in the production of pickles is.  Lactic acid bacteria Which of the following vitamins is lethal in high doses? Vitamin D

What is quickest to become rancid? Butter  The source that fives the highest %CO and NO x  emissions to the atmosphere. Transportation facilities The hierarchy of solid waste management i s. Reduce –  Reuse –  Recycle  –  Treatment –  Disposal  The act of preparing a landfill for long-term inactivity, including  placement of a cover over the landfill to prevent infiltration of surface water. Closure Which of the following are the major components of photochemical smog? Ozone and oxygen This is the total amount of oxygen required to oxidize any organic matter  present in water, i .e. a fter a n extended period such a s 20 or 30 days. Ultimate BOD Glutamic acid (C5H9 NO4) is used as one of the reagents for standard to check the BOD test. Determine the theoretical oxygen demand of 150 mg/L of glutamic acid. Assume the following reactions apply.

C H9 NO  4.5O  → 5CO   3H O  N H NH   2O  → NO−  H +  H O

A sample of radioactive material...0.01% disintegrated after 50 years. What...half-life...material. 8.7 yrs

212mg/L Among...Chalcogen Family, which...non-metallic? Oxygen A liquid generated in landfills is called. Leachate A wastewater treatment plant discharges a flow of 1.5 m 3/s (water plus solids) at a solids concentration of 20 mg/L (20 mg solids per liter of flow, solids plus water). How much solids is the plant discharging each day? 2600kg  A 5 mL wastewater sample was analyzed for its BOD content using the standard BOD test. Initial and fifth day dissolved oxygen was measured as 7.5 and 2.5 respectively. What is the BOD of this sample? 300

Arrange...increasing Ionization energy: C(1) Na(2) Mg(3) B(4) N(5). 23415 Arrange...proton,neutron,electron...mass. E