Q. No.The vapour pressure of 1 molal solution of a non-volatile solute in water at 300 K would be -
(The vapour pressure of water at 300 K = 12.3 kPa)
1.
21.08 kPa
2.
12.08 kPa
3.
33.08 kPa
4.
4.08 kPa
A solution containing 30 g of non-volatile solute in 90 g of water has a vapour pressure of 2.8 kPa at 298 K. Further, 18 g of water is then added to the solution and the new vapour pressure becomes 2.9 kPa at 298 K.
The molar mass of the solute will be -
1. 23 g mol−1
2. 34 g mol−1
3. 15 g mol−1
4. 46 g mol−1
Two elements A and B form compounds having formula AB2 and AB4. When dissolved in 20 g of benzene (C6H6), 1 g of AB2 lowers the freezing point by 2.3 K whereas 1.0 g of AB4 lowers it by 1.3 K. The atomic masses of A and B are respectively -
(Kf for benzene is 5.1 K kg mol-1)
1. 15.59 u and 52.64 u
2. 25.59 u and 42.64 u
3. 13.59 u and 52.64 u
4. 23.59 u and 32.64 u
The type of inter molecular interactions present in
| (a) | n-hexane and n-octane | (i) | Van der Waal’s forces of attraction |
| (b) | NaClO4 and water | (ii) | ion-dipole interaction |
| (iii) | dipole-dipole interaction |
| (a) | (b) | |
| 1. | (i) | (ii) |
| 2. | (ii) | (ii) |
| 3. | (i) | (iii) |
| 4. | (iii) | (iii) |
The insoluble compound in water is /are
1. Phenol
2. Formic acid and toluene
3. Phenol and toluene
4. Toluene and chloroform
If the solubility product of CuS is 6 × 10–16, the maximum molarity of CuS in an aqueous solution will be
| 1. | 1.45 × 10−8 mol L−1 | 2. | 3.45 × 10−8 mol L−1 |
| 3. | 2.45 × 10−8 mol L−1 | 4. | 4.25 × 10−8 mol L−1 |
The mass percentage of aspirin (C9H8O4) in acetonitrile (CH3CN) when 6.5 g of C9H8O4 is dissolved in 450 g of CH3CN will be:
| 1. | 1.424% | 2. | 4.424% |
| 3. | 5.124% | 4. | 2.124% |
The amount of benzoic acid (C6H5COOH) required for preparing 250 mL of 0.15 M solution in methanol is -
| 1. | 4.57 g | 2. | 3.57 g |
| 3. | 1.57 g | 4. | 12.57 g |
The depression in the freezing point of water when 10 g of CH3CH2CHClCOOH is added to 250 g of water will be -
(Ka = 1.4 × 10–3, Kf = 1.86 K kg mol-1)
1. 0.32 K
2. 2.87 K
3. 0.65 K
4. 5.03 K
Henry’s law constant for the solution of methane in benzene at 298 K is 4.27 × 105 mm Hg. The mole fraction of methane in benzene at 298 K under 760 mm Hg will be:
1. 1.85 × 10–5
2. 192 × 10–4
3. 178 × 10–5
4. 18.7 × 10–5
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