Q. No.Match the laws given in Column I with expressions given in Column II.
| Column I | Column II |
| A. Raoult’s law | 1. = CRT |
| B. Osmotic pressure | 2. |
| C. Elevation of boiling point | 3. |
| D. Depression in freezing point | 4. |
Codes
| A | B | C | D | |
| 1. | 2 | 3 | 4 | 1 |
| 2. | 1 | 2 | 3 | 4 |
| 3. | 1 | 4 | 3 | 2 |
| 4. | 3 | 1 | 4 | 2 |
The freezing point of depression constant (Kf ) of benzene is 5.12 K kg mol–1. The freezing point depression for the solution of molality 0.078 m containing a non-electrolyte solute in benzene is:
(rounded off up to two decimal places)
1. 0.80 K
2. 0.40 K
3. 0.60 K
4. 0.20 K
Select the correct option based on statements below:
| Assertion (A): | When NaCl is added to water a depression in freezing point is observed. |
| Reason (R): | The lowering of vapour pressure of a solution causes depression in the freezing point. |
| 1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
| 3. | (A) is True but (R) is False. |
| 4. | (A) is False but (R) is True. |
45 g of ethylene glycol (C2H6O2) is mixed with 600 g of water. The freezing point of the solution is:
1. 268.15 K
2. 270.95 K
3. 272.75 K
4. 267.15 K
\([\text{K}_f \) of the given solvent \( =1.2 \mathrm{K ~kg}~ \mathrm{mol}^{-1}] \)
| 1. | \(242.8 \mathrm{~g} \mathrm{~mol}^{-1}\) | 2. | \(238.2 \mathrm{~g} \mathrm{~mol}^{-1}\) |
| 3. | \(241.8 \mathrm{~g} \mathrm{~mol}^{-1}\) | 4. | \(240.0 \mathrm{~g} \mathrm{~mol}^{-1}\) |
The incorrect statement among the following is:
| 1. | Units of atmospheric pressure and osmotic pressure are the same. |
| 2. | In reverse osmosis, solvent molecules move through a semipermeable membrane from a region of lower concentration of solute to a region of higher concentration. |
| 3. | The value of molal depression constant depends on nature of solvent. |
| 4. | Relative lowering of vapour pressure, is a dimensionless quantity. |
to lower its melting point by 1.5°C, is:
(Kf = 3.9 K kg mol−1)
1. 5.19 g
2. 5.08 g
3. 5.65 g
4. 5.48 g
0.6 mL of acetic acid (CH3COOH), having density 1.06 g mL–1, is dissolved in 1 litre of water. The depression in freezing point observed for this strength of acid was 0.0205°C. The value of van’t Hoff factor and the dissociation constant of acid are respectively:
1. 1.041; 1.86 × 10–5
2. 2.073; 1.86 × 10–5
3. 0.091; 1.76 × 10–5
4. 1.041; 1.76 × 10–5
In comparison to a 0.01 M solution of glucose, the depression in the freezing point of a 0.01 M MgCl2 solution will be:
| 1. | Same | 2. | About twice |
| 3. | About three times | 4. | About six times |
A 5 % solution (by mass) of cane sugar in water has freezing point of 271 K. Freezing point of 5 % glucose in water would be: (freezing point of pure water is 273.15 K)
1. 279.24 K
2. –269.06 K
3. 275.42 oC
4. 269.06 K
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