Two elements A and B form compounds having formula AB₂ and AB₄. When dissolved in 20 g of benzene (C₆H₆), 1 g of AB₂ lowers the freezing point by 2.3 K whereas 1.0 g of AB₄ lowers it by 1.3 K. The atomic masses of A and B are respectively:

(K_f for benzene is 5.1 K kg mol^-1)

1. 15.59 u and 52.64 u

2. 25.59 u and 42.64 u

3. 13.59 u and 52.64 u

4. 23.59 u and 32.64 u

The type of inter-molecular interactions present in:

The insoluble compound in water is /are:

1. Phenol

2. Formic acid and toluene

3. Phenol and toluene 

4. Toluene and chloroform

The mass percentage of aspirin (C₉H₈O₄) in acetonitrile (CH₃CN) when 6.5 g of C₉H₈O₄ is dissolved in 450 g of CH₃CN will be:
1. 1.424%
2. 4.424%
3. 5.124%
4. 2.124%

Nalorphene (C₁₉H₂₁NO₃), similar to morphine, is used to combat withdrawal symptoms in narcotic users. The dose of nalorphene generally given is 1.5 mg.

Calculate the mass of 1.5 × 10⁻³m aqueous solution required for the above dose.
1. 13.22 g
2. 3.22 g
3. 11.22 g
4. 9.22 g

The amount of benzoic acid (C₆H₅COOH) required for preparing 250 mL of 0.15 M solution in methanol is:

The depression in the freezing point of water when 10 g of CH₃CH₂CHClCOOH is added to 250 g of water will be:

 (K_a = 1.4 × 10^–3, K_f = 1.86 K kg mol^–1)

1. 0.32 K

2. 2.87 K

3. 0.65 K

4. 5.03 K

19.5 g of CH₂FCOOH is dissolved in 500 g of water. The van’t Hoff factor and dissociation constant of fluoroacetic acid will be respectively: ($∆{\mathrm{T}}_{\mathrm{f}}$ = 1.00 K )

Henry’s law constant for the solution of methane in benzene at 298 K is 4.27 × 10⁵ mm Hg. The mole fraction of methane in benzene at 298 K under 760 mm Hg will be:

1. 1.85 × 10^–5

2. 192 × 10^–4

3. 178 × 10^–5

4. 18.7 × 10^–5

100 g of liquid A (molar mass 140 g mol^–1) was dissolved in 1000 g of liquid B (molar mass 180 g mol^–1). The vapour pressure of pure liquid B was found to be 500 torr. If the total vapour pressure of the solution is 475 torr, the vapour pressure of pure liquid A will be: