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 |
The van’t Hoff factor, i, for a compound that undergoes
dissociation and association in a solvent is, respectively:
1. Less than one and less than one.
2. Greater than one and less than one.
3. Greater than one and greater than one.
4. Less than one and greater than one.
An aqueous solution is 1.00 molal in KI. The vapour pressure of the solution can be increased by:
1. Addition of NaCl
2. Addition of Na2SO4
3. Addition of 1.00 molal Kl
4. Addition of water
A 0.0020 m aqueous solution of an ionic compound Co(NH3)5(NO2)Cl freezes at -0.0073 oC. The number of moles of ions that 1 mol of ionic compound produces on being dissolved in water will be:
(Kf = -1.86 oC/m)
1. | 2 | 2. | 3 |
3. | 4 | 4. | 1 |
0.5 molal aqueous solution of a weak acid (HX) is 20 % ionised. The lowering in the freezing point of the solution will be:
[Kf for water = 1.86 K kg mol-1]
1. -1.12 K
2. 0.56 K
3. 1.12 K
4. -0.56 K
A solution containing 10 g/dm3 of urea (molecular mass = 60 g mol-1) is isotonic with a 5 % solution of a non-volatile solute. The molecular mass of this non-volatile solute is:
1. | 25 g mol-1 | 2. | 300 g mol-1 |
3. | 350 g mol-1 | 4. | 200 g mol-1 |
1.00 g of non-electrolyte solute (molar mass 250 g mol-1) was dissolved in 51.2 g of benzene. If the freezing point depression constant, Kf of benzene is 5.12 mol-1 kg K, the freezing point of benzene will be lowered by:
1. 0.4 K
2. 0.3 K
3. 0.5 K
4. 0.2 K