The vapour density of undecomposed N₂O₄ is 46. When heated, vapour density decreases to 24.5 due to its dissociation to NO₂. The percent dissociation of N₂O₄ at the final temperature is: 

1. 87                                         

2. 60

3. 40                                         

4. 70

The molal depression constant for water=1.85 deg/molal and for benzene is 5.12 deg/molal. If the ratio of the latent heats of fusion of benzene to water is 3:8, calculate the freezing point of benzene.

1. 6.75$°\mathrm{C}$

2. 5.12$°\mathrm{C}$

3. 8.97$°\mathrm{C}$

4. 6.1$°\mathrm{C}$

Which of the following colligative properties is associated with the concentration term 'molarity'?

1. Lowering of vap.pressure

2. Osmotic pressure

3. Depression in freezing point

4. Elevation in boiling point

The vapour pressure of a dilute aqueous solution of glucose is 750 mm of Hg at 373 K. The mole fraction of solute in the solution is-
1. 1/10
2. 1/76
3. 1/7.6
4. 1/35

Which pair of solutions is likely to exhibit isotonicity at a constant temperature?

1. 0.1 (M) Urea and 0.1 (M) NaCl

2. 0.1 (M) Urea and 0.2 (M) MgCl₂

3. 0.1 (M) NaCl and 0.1 (M) Na₂SO₄

4. 0.1 (M) Ca(NO₃)₂ and 0.1 (M) Na₂SO₄

The latent heat of vapourisation of water is 540 cal g^-1 at 100$°\mathrm{C}$. K_b for water is

1. 0.56 K.mole^-1

2. 1.86 K.mole^-1

3. 0.51 K.mole^-1

4. 5.12 K.mole^-1

Which of the following aqueous solution has osmotic pressure nearest to that an equimolar solution of K₄[Fe(CN)₆]?

1. Na₂SO₄

2. BaCl₂

3. Al₂(SO₄)₃

4. C₁₂H₂₂O₁₁

The ratio of the vapour pressure of a solution to the vapour pressure of the solvent is

1. Equal to the mole fraction of the solvent

2. Proportional to the mole fraction of the solute

3. Equal to the mole fraction of the solute

4. None of the above

The partial pressure of ethane over a saturated solution containing 6.56 X 10^-2 g of ethane is 1 bar. If the solution contains 5.00 X 10^-2 g of ethane, then what shall be the partial pressure of the gas?

1. 0.76 bar

2. 0.16 bar

3. 1.16 bar

4. 3.12 bar

An aqueous solution of hydrochloric acid -

1. Obeys Raoult's law

2. Shows negative deviations from Raoult's law

3. Shows positive deviations from Raoult's law

4. Obeys Henry's law at all compositions