A solution of urea (molar mass 56 g mol–1) boils at 100.18 ºC at atmospheric pressure. If Kf and Kb for water are 1.86 and 0.512 K kg mol–1 respectively, the above solution will freeze at:
1. –6.54 ºC
2. –0.654 ºC
3. 6.54 ºC
4. 0.654 ºC
A solution has a 1:4 mole ratio of pentane to hexane.
The vapor pressures of the pure hydrocarbons at 20 ºC are
440 mm Hg for pentane and 120 mm Hg for hexane.
The mole fraction of pentane in the vapor phase would be:
1. | 0.200 | 2. | 0.478 |
3. | 0.949 | 4. | 0.786 |
The addition of water vapour does not change the density of:
1. CCl4
2. CS2
3. Ether
4. Coke
1 % (w/w) solution of a compound is isotonic with 5 % (w/w) sucrose (sugar) solution. The molecular weight of the compound will be:
1. | 32.4 | 2. | 68.4 |
3. | 129.6 | 4. | 34.2 |
The vapour pressure of a solvent decreased by 10 mm of Hg when a non-volatile solute was added to the solvent. The mole fraction of the solute in solution is 0.2. What would be the mole fraction of the solvent if the decrease in vapour pressure is 20 mm of Hg:
1. 0.2
2. 0.4
3. 0.6
4 0.8
From the colligative properties of a solution, which one is the best method for the determination of molecular weight of proteins & polymers:
1. Osmotic pressure
2. Lowering of vapour pressure
3. Lowering of freezing point
4. Elevation in boiling point
A solution contains a non-volatile solute of molecular mass M2. The molecular mass of solute in terms of osmotic pressure is:
where:
m2 → Mass of solute
V → Volume of solution
\(\pi\) → Osmotic pressure
1.
2.
3.
4.
The ideal solution indicates:
1. | A – B attraction force is greater than A – A and B – B. |
2. | A – B attraction force is less than A – A and B – B. |
3. | Attraction force remains the same in A – A and B – B. |
4. | The volume of the solution is different from the sum of the volume of the solute and solvent. |
Beans get cooked earlier in a pressure cooker, because:
1. | The boiling point increases with increasing pressure |
2. | The boiling point decreases with increasing pressure |
3. | The extra pressure of the pressure cooker softens the beans |
4. | Internal energy is not lost while cooking in a pressure cooker |
The vapour pressure of two liquids 'P' and 'Q' are 80 and 60 torr, respectively. The total vapour pressure of the solution obtained by mixing 3 moles of P and 2 moles of Q would be:
1. 68 torr
2. 140 torr
3. 72 torr
4. 20 torr