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

Which solution will have the highest boiling point ?

1. 1 (M) C₆H₁₂O₆ solution

2. 1 (M) NaCl solution

3. 1 (M) BaCl₂ solution

4. 1 (M) CO(NH₂)₂ solution

20g of naphthoic acid (C₁₁H₈O₂) dissolved in 50g of benzene (K_f=1.72 K Kg mol^-1) shows a depression in freezing point of 2K. The Vant Hoff factor is?

1. 0.5

2. 0.1

3. 2

4. 3

When 0.1 m CH₃COOH is present in a solvent it shows elevation in boiling point of 0.75$°\mathrm{C}$. Acid dissociation constant will be -(K_b=5 K Kg mol^-1) (1M =1m)

(1) 5 X 10^-2

(2) 5 X 10^-3

(3) 10^-2

(4) 10^-3 

A solute x when dissolved in solvent associates to form a pentamer. The value of van't hoff factor (i) for the solute will be:-

1. 0.5

2. 5

3. 0.2

4. 0.1