ChE Reviewer 2014 (PART I)

1. Which of the following statements best describes what happens when chocolate melts? a) This is a physical change, and the molecules move farther apart. b) This is a chemical change, and the molecules move farther apart. c) This is a physical change, and the molecules move closer together. d) This is a chemical change, and the molecules move closer together. 2. Which of the following is not part of Dalton’s atomic theory? a) All matter is composed of indivisible atoms. b) Atoms of the same element can be different. c) Compounds form when atoms combine in whole number ratios. d) A chemical reaction involves rearrangement of atoms.

11. Which statement best describes the chemistry of soaps? a) They contain both a nonpolar group and a polar group b) They contain only a nonpolar group c) They contain only a charged group d) They are highly polar, charged compounds 12. Which of the following is not true about acidbase indicators? a) They act as sensors of H+ by changing color. b) They account for the fact that roses are red and violets are blue. c) They are found in pH paper. d) They form the basis of the Scott test for cocaine.

3. Which of the following pairs of compounds illustrates the law of multiple proportions? a) Fe, FeO3 b) Cl, Cl2 c) H2SO4, NaOH d) H2O, H2O2

13. Isomers are molecules with the same a) kinds and number of atoms but a different arrangement of these atoms b) number of electrons and protons but a different number of neutrons c) net dipole but different atoms involved in the bond d) molecular formula but a different overall charge

4. Which of the following elements would you expect to behave most like magnesium? a) sodium b) calcium c) aluminum d) scandium

14. Which of the following elements has the greatest electronegativity? a) S b) He c) Fr d) Cl

5. Which of the following has the longest wavelength? a) X rays b) microwaves c) green light d) UV light

15. Your friend is abroad this semester in London. She reports that the temperature there is 4°C. You know that the conversion to Fahrenheit involves multiplying by 1.8 and adding 32°F. What is the London temperature in Fahrenheit with the correct number of significant figures? a) 39.2°F b) 39°F c) 40°F d) 4°F

6. Which of the following represents the correct formula of the compound formed by fluorine and aluminum? a) Al3F7 b) Al5F c) AlF3 Al7F3 d) Al7F3 7. Which of the following is an ionic compound? a) N2O b) CO c) HCl d) Na2O 8. What is the molar mass of acetaminophen, shown here? a) 151 g/mol b) 48 g/mol c) 120 g/mol d) 132 g/mol 9. Which of the following is most likely to lose electrons in an ionic compound? a) oxygen (O) b) hydrogen (H) c) lead (Pb) d) carbon (C) 10. Which of the following is the least active metal? a) aluminum b) gold c) iron d) magnesium

16. The t-butyl carbocation is stabilised by hyperconjugation of the positive charge through the _________ orbitals. a) s/p b) p/p c) sp2/sp3 d) p/sp3 17. Which one of the following elements does not

exist as a diatomic molecule in nature? a) hydrogen b) nitrogen c) fluorine d) neon For questions 18. and 19., consider the following reaction: 4 Al (s) + 3 O2 (g) ⇒ 2 Al2O3 (s) 18. The reaction can be classified as which one of the following types? a) precipitation b) decomposition c) synthesis d) double displacement

19. How many moles of Al2O3 can be produced from the reaction of 10.0 g of Al and 19.0 g of O2? a) 0.581 mol b) 0.371 mol c) 0.185 mol d) 0.396 mol

a) c)

20. What volume of 12.0 M HCl is required to make 75.0 mL of 3.50 M HCl? a) 21.9 mL b) 0.560 mL c) 257 mL d) 75.0 mL

26. The mass of P4O10 that will be obtained from the reaction of 1.33 gram of P4 and 5.07 of oxygen is a) 2.05 gram b) 3.05 gram c) 4.05 gram d) 5.05 gram

For questions 21. and 22., consider the following heating curve of a hypothetical substance:

helium oxygen

b) d)

ozone methane

27. The octane number of zero is assigned to a) 2-methyl octane b) n-heptane c) iso-octane d) 3-methyl octane 28. The metal that is used as a catalyst in the hydrogenation of oils is a) Ni b) Pb c) Cu d) Pt

21. What is the boiling point of the substance? a) 0°C c) 12°C b) −50°C d) 75°C 22. What state of matter is the substance at 50°C? a) gas c) solid b) liquid d) not enough information 23. The metallurgical process in which a metal is obtained in a fused state is called a ) smelting c) calcinations

b) roasting d) froth floatation

24. The law which states that the amount of gas dissolved in a liquid is proportional to its partial pressure is a) Dalton's law b) Gay Lussac's law c) Henry's law d) Raoult's law 25. The gas present in the stratosphere which filters out some of the sun's ultraviolet light and provides an effective shield against radiation damage to living things is

29. The Latin word formica means ant. The name formic acid is derived from this Latin word because a) this acid, in ancient times, was used to eliminate ant-hills b) this corrosive acid is secreted by ants to drive away their enemies c) this acid was first obtained by the distillation of ants d) ants are attracted by the odour of this acid 30. The monomer of polythene is a) b) c) d)

vinyl chloride ethylene ethyl alcohol None of the above

31. The luster of a metal is due to a) its high density b) its high polishing c) its chemical inertness d) presence of free electrons 32. The number of water molecules present in a drop of water (volume 0.0018 ml) at room temperature is a) 1.568 x 103 b) 6.023 x 1019 c) 4.84 x 1017 d) 6.023 x 1023

33. The most malleable metal is a) platinum b) c) iron d)

silver gold

34. The oil used in the froth floatation process is a) coconut oil b) olive oil c) kerosene oil d) pine oil 35. The mass of one Avogadro number of helium atom is a) 1.00 gram b) 4.00 gram c) 8.00 gram d) 4 x 6.02 x 1023 gram 36. The inexpensive and commonly used variety of glass is called soda glass. It is called so because a) was used initially for making bottles of soda(carbonated drink) b) is made using soda(sodium carbonate) c) was initially used for storing sodium carbonate d) is made using soda lime 37. The graphite rods in the nuclear reactor a) react with U to release energy b) produce neutrons c) undergo combustion which triggers the nuclear fission d) convert fast moving neutrons into thermal neutrons 38. The first metal used by man was a) iron b) copper c) gold d) bronze

42. The molecule which has the highest percentage of ionic character among the following is a) HI b) HF c) HCI d) HBr 43. The iron ore magnetite consists of A. Fe2O3 B. Fe3OH4 C. FeCO3 D. 3Fe2O3 .. 3H2O 44. The main chemical constituent of clay is a) silicon oxide b) aluminium borosilicate c) zeolites d) aluminium silicate 45. The mineral containing both magnesium and calcium is a) magnesite b) calcite c) carnallite d) dolomite 46. The metal does not give H2 on treatment with dilute HCL is a) Zn b) Fe c) Ag d) Ca 47. The number of g-molecule of oxygen in 6.02 x 1024CO molecules is a) 1 gram of molecule b) 0.5 gram of molecule c) 5 gram of molecule d) 10 gram of molecule 48. The maximum number of isomers for an alkene with molecular formula C4H8 is a) 5 b) 4 c) 2 d) 3 49. The most important ore of aluminium is

39. The most electropositive elements among the following is a) Na b) Ca c) K d) Cs 40. The method that cannot be used for removing permanent hardness of water is a) adding sodium carbonate b) distillation c) adding caustic soda d) boiling 41. Zone refining is used for the purification of a) Au b) Ge c) Ag d) Cu

a) c)

bauxite haematite

b) d)

magnetite monazite

50. The hottest part of the gas flame is known as a) luminous zone b) dark zone c) blue zone d) non-luminous zone 51. The isomerism which exists between CH3CHCI2 and CH2CI. CH2CI is a) chain isomerism b) functional group isomerism c) positional isomerism d) metamerism

52. The half life period of an isotope is 2 hours. After 6 hours what fraction of the initial quantity of the isotope will be left behind? a) 1/6 b) 1/3 c) 1/8 d) ¼ 53. The number of atoms present in 21.6 gram of silver (atomic weight = 108) are same as the molecules in a) 1.8 gram of H2O b) 12 moles of KMnO4 c) 0.6N H2SO4 d) 4.6 gram of C2H5OH 54. The mass number of an atom is equal to a) the number of protons b) the number of protons and electrons c) the number of nucleons d) the number of neutrons 55. The formula C6H5-CO-CH3 represents a) Acetone b) Acetic acid c) Acetophenone d) Phenyl acetate 56. The metal that is usually extracted from sea water is a) Ca b) Na c) K d) Mg 57. The method of concentrating the ore which makes use of the difference in density between ore and impurities is called a) liquation b) leaching C) levigation d) magnetic separation 58. The molecular formula of phosphorous is a) P1 b) P2 c) P3 d) P4 59. Maximum work that could be secured by expanding the gas over a given pressure range is the __________ work. a) isothermal b) adiabatic c) isentropic d) none of these 60. Heating of water under atmospheric pressure is an __________ process. a) isochoric b) isobaric c) adiabatic d) isothermal

61. Van Laar equation deals with the activity coefficients in a) binary solutions b) ternary solutions c) azeotropic mixture only d) none of these 62. High __________ is an undesirable property for a good refrigerant. a) specific heat b) latent heat of vaporisation c) viscosity d) specific vapor volume 63. The accentric factor of a materical, 'ω', is defined as ω = -log10(Prsat)Tr-1 = 0.7, where, Prsat = reduced vapor pressure, Tr = reduced temperature. The value of accentric factor is always a) >2 b) 1 d)