Solutions · Question 22

A substance 'X' (1.5 g) dissolved in 150 g of a solvent 'Y' (molar mass = 300 g mol-1) led to an elevation of the boiling point by 0.5 K. The relative lowering in the vapour pressure of the solvent 'Y' is 10-2. (nearest integer) [Given: Kb of the solvent = 5.0 K kg mol-1] Assume the solution to be dilute and no association or dissociation of X takes place in solution.

HA(aq) H+(aq) + A-(aq) The freezing point depression of a 0.1 m aqueous solution of a monobasic weak acid HA is 0.20 C. The dissociation constant for the acid is Given: Kf(H2O) = 1.8 K kg mol-1, molality ≡ molarity

1. 1.90 10-3
2. 1.38 10-3
3. 1.1 10-2
4. 1.89 10-1

Which of the following binary mixtures does not show the behaviour of minimum boiling azeotropes?

1. CH3OH + CHCl3
2. C6H5OH + C6H5NH2
3. H2O + CH3COC2H5
4. CS2 + CH3COCH3

The percentage dissociation of a salt (MX3) solution at given temperature (van't Hoff factor i = 2) is % (Nearest integer)

Liquid A and B form an ideal solution. The vapour pressures of pure liquids A and B are 350 and 750 mm Hg respectively at the same temperature. If xA and xB are the mole fraction of A and B in solution while yA and yB are the mole fraction of A and B in vapour phase, then,

1. (xA - yA) < (xB - yB)
2. xAxB = yAyB
3. xAxB < yAyB
4. xAxB > yAyB

Match List - I with List - II. Choose the correct answer from the options given below :

1. A-III, B-I, C-IV, D-II
2. A-III, B-IV, C-I, D-II
3. A-II, B-I, C-IV, D-III
4. A-II, B-IV, C-I, D-III

XY is the membrane/partition between two chambers 1 and 2 containing sugar solutions of concentration c1 and c2 (c1 > c2) mol L-1. For the reverse osmosis to take place identify the correct condition. (Here p1 and p2 are pressures applied on chamber 1 and 2.) [figure] Choose the correct answer from the options given below:

1. A and C Only
2. A and D Only
3. B and D Only
4. C Only

Given below are two statements: In the light of the above statements, choose the most appropriate answer from the options given below :

1. Statement I is correct but Statement II is incorrect
2. Both Statement I and Statement II are incorrect
3. Statement I is incorrect but Statement II is correct
4. Both Statement I and Statement II are correct

Sea water, which can be considered as a 6 molar (6 M) solution of NaCl, has a density of 2 g mL-1. The concentration of dissolved oxygen (O2) in sea water is 5.8 ppm. Then the concentration of dissolved oxygen (O2) in sea water, in terms of molality, is x 10-4 m. x = . (Nearest integer) Given: Molar mass of NaCl is 58.5 g mol-1 Molar mass of O2 is 32 g mol-1

2 moles each of ethylene glycol and glucose are dissolved in 500 g of water. The boiling point of the resulting solution is: (Given : Ebullioscopic constant of water = 0.52 K kg mol-1)

1. 377.3 K
2. 379.2 K
3. 375.3 K
4. 277.3 K