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Concentration methods 29. In which mode of expression the concentration of solution remains independent of temperature 1) Molarity 32.

34.

36.

3) 400

4) 1000

2) decrease in molarity

3) decrease in mole fraction

4) decrease in % W/W

Which of the following solutions has the highest normality 2) N-Phosphoric acid 3) 6g of NaOH/100 ml4) 0.5m H2SO4

Hydrochloric acid solutions A and B have concentrations of 0.5 N and 0.1 N respectively. The volumes of solutions A and B required to make 2 litres of 0.2 NHCl are 1) 0.5lit of A+1.5lit of B

2) 1.5lit of A+0.5lit of B

3) 1.0lit of A+1.0lit of B

4) 0.75lit of A+1.25lit of B

The molarity of pure water is 2) 50

3) 100

4) 18

The mole fraction of water in 20% aqueous solution of H2O2 is 1) 77 68

38.

2) 200

1) decrease in molality

1) 55.6 37.

4) Molality

Increasing the temperature of an aqueous solution will cause

1) 1.8g of KOH/1 lit. 35.

3) Formality

A 500g tooth paste sample has 0.2g fluoride concentration. What is the concentration of F in terms of ppm level? 1) 250

33.

2) Normality

2) 68 77

3) 20 80

4) 80 20

Volume of 0.1M K2Cr2O7 required to oxidises 35ml of 0.5M FeSO4 solution is 1) 29 ml

2) 87 ml

3) 175 ml

4) 145 ml

Vapour pressure 51.

The vapour pressure of a liquid in a closed container depends upon 1) amount of liquid 3) temperature

2) surface area of the container 4) none of the above

52. the

The temperature at which the vapour pressure is equal to the external pressure is called

1) critical temperature

2) boiling point

3) normal point

4) saturation point

3.5

The incorrect statement is : (A) Vapour pressure of a liquid always increases by increasing temperature. (B) Vapour pressure only depends on temperature and not on the nature of substance. (C) Vapour pressure does not depend on the quantity of the liquid taken and the surface area of the liquid. (D) Vapour pressure is not a colligative property & is independent of the concentration of the liquid.

3.11

A sample of air is saturated with benzene (vapor pressure = 100 mm Hg at 298 K) at 298K, 750mm Hg pressure. If it is isothermally compressed to one third of its initial volume, the final pressure of the system is (A) 2250 torr (B) 2150 torr (C) 2050 torr (D) 1950 torr

Vapour pressure of non volatile solutes 8.

The V.P. of a dilute solution of a non-volatile solute is P and the V.P. of pure solvent is P0, the lowering of the V.P. is 1) + Ve

72.

2) – Ve

82.

4) P0 P

“Relative lowering in vapour pressure” of a solution containing one mol. K2SO4 in 54gm H2O is (K2SO4 in 100% ionized) 1) 1 55

81.

3) P P0

2) 3 58

3) 3 4

4) 1 2

If relative decrease in V.P is 0.4 for a solution containing 1 mol. NaCl in 3 mol. H2O, NaCl is ….. % ionised 1) 60% 2) 50% 3) 100% 4) 40% Three solutions are prepared by adding 'w' gm of 'A' into 1kg of water, 'w' gm of 'B' into another 1 kg of water and 'w' gm of 'C' in another 1 kg of water (A, B, C are non electrolytic). Dry air is passed from these solutions in sequence (A B C). The loss in weight of solution A was found to be 2 gm while solution B gained 0.5 gm and solution C lost 1 gm. Then the relation between molar masses of A, B and C is (A) M A : M B : M C = 4 : 3 : 5

(B) M A : M B : M C =

(C) M C > M A > M B

(D) M B > M A > M C

1 1 1 : : 4 3 5

Vapour pressure of volatile solutes

79.

An ideal binary liquid solution, the plot of Ptotal versus XA (mole fraction of liquid A) is linear with slope and intercept equal to 1) PA0 - PB0 , PA0

80.

2) PA0 - PB0 , PB0

3) PB0 - PA0 , PA0

4) PB0 - PA0 , PB0

Mole fraction of A vapours above solution in mix of A and B  XA = 0.4 will be

PA0  100mm, PB0  200mm 1) 0.4 12.

2) 0.8

3) 0.25

4) none

When an ideal binary solution is in equilibrium with its vapour, molar ratio of the two components in the solution and in the vapour phase is 1) same

2) different

3) may or may not be same depending upon volatile nature of the two components 77.

Mixture of volatile component to A and B has total V.P, P = 254 – 119x (x = mo. Fraction of B) Hence PA0 and PB0 are 1) 135, 254

68.

3) 254, 135

4) 135, 119

If PA is the vapour pressure of a pure liquid A and the mole fraction of A in the mixture of two liquids A and B is x the partical vapour pressure of A is 1) (1 – x)PA

26.

2) 119, 254

2) x PA

3) x (1- x)PA

4) 1- x x  PA

For an ideal binary liquid solution with PA0 > PB0 , which of the following relations between XA (mole fraction of A in liquid phase) and YA (mole fraction A in vapour phase) is correctly represented? 1) XA = YB

2) XA > YA

3) XA < YA

4) XA and YA cannot be correlated with each other 24. Which of the following plots does not represent the behaviour of an ideal binary liquid solution? 1)

Plot of PA versus XA (mole fraction A in liquid phase) is linear

2)

Plot of PB versus XB is linear

3)

Plot of Ptotal versus XA (or XB) is linear 4)

Plot of Ptotal versus XA is non linear

25. Which of the following plots correctly represents the behaviour of an ideal binary liquid solution? 1) Plot of XA (mole fraction of A in liquid phase) versus YA (mole fraction of A in vapour phase) is linear 2) Plot of XA versus YB is linear 3) Plot of 1 X A versus 1 YA is linear 4) Plot of 1 X A versus 1 YB is linear 70.

The most likely of the following mixtures to be an ideal solution is 1) NaCl – H2O

27.

2) C2H5- OH – C6H6

3) C7H16(l) – H2O

4) C7H16(l) C8H18(l)

A binary liquid solution of chloroform and acetone is prepared. Which of the following statements correctly represents the behaviour of this liquid solution? 1) The solution formed is an ideal solution 2) The solution formed is non ideal solution with positive deviations from Raoult‟s law 3) The solution formed is non ideal solution with negative deviations from Raoults law

4) Chloroform exhibits positive deviation whereas acetone exhibits negative deviation from Raoult‟s law 42.

Which of the following pairs shows a positive deviation from Raoult‟s law? 1) Water-hydrochloric acid

2) Water-nitric acid

3) Acetone-Chloroform

4) Benzene-methanol

1. An azeotropic mixture of two liquids boils at a lower temperature than either of them when 1) it is saturated

2) it does not deviate from Raoult‟s law

3) it shows negative deviation from Raoult‟s law 4) it shows positive deviation from Raoult‟s law 19.

A maxima or minima obtained in the temperature composition curve of a mixture of two liquids indicates?

1) An azeotropic mixture

2) a eutectic formation

3) that the liquids are immiscible with one another 4) that the liquids are partially miscible at the maximum or minimum 41.

100ml of a liquid A was mixed with 25ml of a liquid B to give a non-ideal solution of A-B mixture. The volume of this mixture would be 1) 75 ml

2) 125 ml

3) just more than 125 ml

4) close to 125ml but not exceeding 125ml 82.





1 mol A+ 3 mol B (volatile liquids) PA0 = 300mm, PB0 =100mm , mol fraction of B in vapour state above solution is 1) 0.75

83.

84.

3) 0.50

4) 0.66

Which is true about ideal solutions 1) the change in volume of mixing is zero

2) the change enthalpy of mixing is zero

3) both 1 and 2

4) none of these

Vapour pressure of A is 100mm and that of B is 200mm, mol. fraction of A in vapour state in the mixture of 3 mol of A and 1 mol of B is 1) 0.4

85.

2) 0.25

2) 0.6

3) 1.0

4) 0.8

Vapour pressure of mixture of above question is 1) 125 mm

2) 50 mm

3) 200 mm

4) 300 mm

86.

An ideal mixture of liquids A and B with 2 moles of A and 2 moles of B has a total vapour pressure of 1 atm at a certain temperature. Another mixture with 1 mole of A and 3 moles of B has a vapour pressure greater than 1 atm. But if 4 moles of C are added to the second mixture, the vapour pressure comes down to 1 atm. Vapour pressure of C, Pc0 = 0.8 atm. Calculate the vapour pressures of pure A and pure B. (A) PA0 = 1.4 atm, PB0 = 0.7 atm (B) PA0 = 1.2 atm, PB0 = 0.6 atm (C) PA0 = 1.4 atm, PB0 = 0.6 atm (D) PA0 = 0.6 atm, PB0 = 1.4 atm

88.

Based on the given diagram, which of the following statements regarding the solutions of two miscible volatile liquids are correct?

(1)

Plots AD and BC show that Raoult‟s law is obeyed for the solution in which B is a solvent and A is the solute and as well as for that in which A is solvent and B is solute

(2)

Plot CD shows that Daltons law of partial pressures is observed by the binary solutions of components A and B

(3)

EF+BG=GH, and AC and BD correspond to the vapour pressures of the pure solvents A and B respectively. Select the correct answer using the codes given below

1) 1 and 2 89.

2) 2 and 3

3) 1 and 3

4) 1, 2 and 3

An ideal liquid solution, the plot of 1 X A versus 1 YA (where X A and YA are the mole fractions of A in liquid and vapour phase) is linear with slope and intercept equal to 1)

PB0 - PA0 PA0 , 0 PB0 PB

2)

PB0 - PA0 PB0 , 0 PB0 PA

3)

PA0 PB0 - PA0 , PB0 PB0

4)

PB0 PB0 - PA0 , PA0 PB0

Van’t Hoff factor 58.

Which of the following correctly expresses the Van‟t Hoff factor? 1) Calculated osmotic pressure / Observed osmotic pressure 2) Observed molecular weight / Calculated molecular weight 3) Calculated boiling point / Observed boiling point 4) Observed colligative property / Calculated colligative property

9.

The Vant Hoff factor NaCl assuming 100% dissociation is 1) 1 2

59.

3) 1

4) 3

3) = 1

4) none of the above

Van‟t Hoff factor for an electrolyte is 1) > 1

60.

2) 2

2) < 1

Acetic acid dissolved in benzene shows a molecular mass of 1) 30

2) 60

3) 120

4) 180

61. The ratio of the value of any colligative property for KCL solution to that of sugar solution is nearly

1) 1 62.

64.

2) 87%

3) 100%

4) 74%

1) Ionisation of benzoic acid

2) Dimerisation of benzoic acid

3) Trimerization of benzoic acid

4) Solvation of benzoic acid

Benzoic acid undergoes dimerisation in benzene solution, the Van‟t Hoff factor „i‟ is related to the degree of association „x‟ of the acid is 2) i = (1+x)

3) i = 1 - x 2

4) i = 1 + x 2

Van‟t Hoff‟s factor for K3  Fe(CN)6  (ionization 50%) will be 1) 1

13. are

4) 2.5

The molecular weight of benzoic acid in benzene as determined by depression in freezing point method corresponds to

1) i = (1- x) 73.

3) 2

The Van‟t Hoff factor for 0.1M Ba(NO3)2 solution is 2.74. The degree of dissociation is 1) 91.3%

63.

2) 0.5

2) 5.5

3) 2.5

4) none

The lowering of vapour pressure of 0.1 M aqueous solution of NaCl, CuSO4 and K2SO4

1) all equal 3) in the ratio 3 : 2 : 1

2) in the ratio 1 : 1 : 1.5 4) in the ratio 1.5 : 1 : 2.5