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
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. |
Which of the following mixtures forms the maximum boiling azeotrope?
1. | Heptane + Octane | 2. | Water + Nitric acid |
3. | Ethanol + Water | 4. | Acetone + Carbon disulphide |
A solution of sucrose (molar mass = 342 g mol–1) has been prepared by dissolving 68.5 g of sucrose in 1000 g of water. The freezing point of the solution obtained will be:
(kf for water = 1.86 K kg mol–1)
1. –0.372 oC
2. –0.520 oC
3. +0.372 oC
4. –0.570 oC
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 |
pA and pB are the vapour pressure of pure liquid components, A and B, respectively of an ideal binary solution.
If XA represents the mole fraction of component A, the total pressure of the solution will be:
1. pA + XA (pB-pA)
2. pA + XA (pA-pB)
3. pB + XA (pB-pA)
4. pB + XA (pA-pB)
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]