Solutions

When 1 g each of compounds AB and AB2 are dissolved in 15 g of water separately, they increased the boiling point of water by 2.7 K and 1.5 K respectively. The atomic mass of A (in amu) is 10-1 (Nearest integer) (Given : Molal boiling point elevation constant is 0.5 K kg mol-1)

1.24 g of AX2 (molar mass 124 g mol-1) is dissolved in 1 kg of water to form a solution with boiling point of 100.0156°C, while 25.4 g of AY2 (molar mass 250 g mol-1) in 2 kg of water constitutes a solution with a boiling point of 100.0260°C. Kb(H2O) = 0.52 kg mol-1 Which of the following is correct?

1. AX2 and AY2 (both) are completely unionised.
2. AX2 and AY2 (both) are fully ionised.
3. AX2 is completely unionised while AY2 is fully ionised.
4. AX2 is fully ionised while AY2 is completely unionised.

If A2B is 30% ionised in an aqueous solution, then the value of van't Hoff factor (i) is 10-1.

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

1. Both Statement I and Statement II are false
2. Statement I is true but Statement II is false
3. Both Statement I and Statement II are true
4. Statement I is false but Statement II is true

What is the freezing point depression constant of a solvent, 50 g of which contain 1 g non-volatile solute (molar mass 256 g mol-1) and the decrease in freezing point is 0.40 K?

1. 4.43 K kg mol-1
2. 3.72 K kg mol-1
3. 5.12 K kg mol-1
4. 1.86 K kg mol-1

Assume a living cell with 0.9% (w/w) of glucose solution (aqueous). This cell is immersed in another solution having equal mole fraction of glucose and water. (Consider the data upto first decimal place only) The cell will :

1. shrink since solution is 0.45% (w/w) as a result of association of glucose molecules (due to hydrogen bonding)
2. shrink since solution is 0.5% (w/w)
3. show no change in volume since solution is 0.9% (w/w)
4. swell up since solution is 1% (w/w)

Consider the given plots of vapour pressure (VP) vs temperature (T/K). Which amongst the following options is correct graphical representation showing Tf, depression in the freezing point of a solvent in a solution?

1. [figure]
2. [figure]
3. [figure]
4. [figure]

The observed and normal molar masses of compound MX2 are 65.6 and 164 respectively. The percent degree of ionisation of MX2 is %. (Nearest integer)

CrCl3 xNH3 can exist as a complex. 0.1 molal aqueous solution of this complex shows a depression in freezing point of 0.558 C. Assuming 100% ionisation of this complex and coordination number of Cr is 6, the complex will be (Given Kf = 1.86 K kg mol-1)

1. [Cr(NH3)5Cl]Cl2
2. [Cr(NH3)4Cl2]Cl
3. [Cr(NH3)6]Cl3
4. [Cr(NH3)3Cl3]

When a non-volatile solute is added to the solvent, the vapour pressure of the solvent decreases by 10 mm of Hg. The mole fraction of the solute in the solution is 0.2. What would be the mole fraction of the solvent if decrease in vapour pressure is 20 mm of Hg ?

1. 0.2
2. 0.4
3. 0.8
4. 0.6