The equal weight of a solute is dissolved in an equal weight of two solvents A and B to form a very dilute solution. The relative lowering of vapour pressure for solution B has twice the relative lowering of vapour pressure for solution A.
If and are the molecular weights of solvents A and B respectively, then:
1. =
2. = 2
3. = 4
4. = 2
The van’t Hoff factor (i) for a dilute aqueous solution of a strong electrolyte barium hydroxide is:
1. 0
2. 1
3. 2
4. 3
Consider the following statements about the composition of the vapour over an ideal 1:1 molar mixture of benzene and toluene. The correct statement is:
Assume that the temperature is constant at 25 oC.
(Given, vapour pressure data at 25 °C, benzene = 12.8 kPa, toluene = 3.85 kPa)
1. | The vapour will contain a higher percentage of toluene. |
2. | The vapour will contain equal amounts of benzene and toluene. |
3. | Not enough information is given to make a prediction. |
4. | The vapour will contain a higher percentage of benzene. |
The boiling point of 0.2 mol kg–1 solution of X in water is greater than the equimolal solution of Y in water. The correct statement in this case is:
1. | X is undergoing dissociation in water. |
2. | Molecular mass of X is greater than the molecular mass of Y. |
3. | Molecular mass of X is less than the molecular mass of Y. |
4. | Y is undergoing dissociation in water while X undergoes no change. |
The electrolyte having the same value of Van't Hoff factor (i) as that of Al2(SO4)3 (if all are 100% ionized) is:
1. K2SO4
2. K3[Fe(CN)6]
3. Al(NO3)3
4. K4[Fe(CN)6]
The largest freezing point depression among the following 0.10 m solutions is shown by:
1. | \(\mathrm{KCl}\) | 2. | \(\mathrm{C_6H_{12}O_6}\) |
3. | \(\mathrm{Al}_2(\mathrm{SO_4})_3\) | 4. | \(\mathrm{K_2SO_4}\) |
The freezing point depression constant for water is 1.86 oC m-1. If 5.00 g Na2SO4 is dissolved in 45.0 g H2O,
the freezing point is changed by -3.82 oC. The Van’t Hoff factor for Na2SO4 is:
1. | 2.63 | 2. | 3.11 |
3. | 0.381 | 4. | 2.05 |