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
1. Benzene + Toluene
2. Acetone + Chloroform
3. Chloroethane + Bromoethane
4. Ethanol + Acetone
If 8 g of a non-electrolyte solute is dissolved in 114 g of n-octane to reduce its vapor pressure to 80 %, the molar mass (in g mol–1) of the solute is:
[Molar mass of n-octane is 114 g mol–1]
1. | 40 | 2. | 60 |
3. | 80 | 4. | 20 |
Isotonic solutions have the same:
1. Vapour pressure
2. Freezing temperature
3. Osmotic pressure
4. Boiling temperature
The correct statement regarding a solution of two components A and B exhibiting positive deviation from ideal behaviour is :
1. | Intermolecular attractive force between A-A and B-B are stronger than those between A-B |
2. | ∆mixH = 0 at constant T and P |
3. | ∆mixV = 0 at constant T and P |
4. | Intermolecular attractive forces between A-A and B-B are equal to those between A-B |
Which of the following mixtures forms the maximum boiling azeotrope?
1. | Heptane + Octane | 2. | Water + Nitric acid |
3. | Ethanol + Water | 4. | Acetone + Carbon disulphide |
During osmosis, the flow of water through a semi-permeable membrane is:
1. | From a solution having higher concentration only. |
2. | From both sides of the semi-permeable membrane with equal flow rates. |
3. | From both sides of the semi-permeable membrane with unequal flow rates. |
4. | From a solution having lower concentration only. |
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
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 |
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