The vapour pressures of pure benzene and toluene are 160 torr and 60 torr, respectively. The mole fraction of toluene in the vapour phase in contact with an equimolar solution of benzene and toluene will be:

1. 0.50

2. 0.6

3. 0.27

4. 0.73

1. Benzene + Toluene

2. Acetone + Chloroform

3. Chloroethane + Bromoethane

4. Ethanol + Acetone

The freezing point of depression constant (K_f ) of benzene is 5.12 K kg mol^–1. The freezing point depression for the solution of molality 0.078 m containing a non-electrolyte solute in benzene is:
(rounded off up to two decimal places)
1. 0.80 K
2. 0.40 K
3. 0.60 K
4. 0.20 K

For a solution, the plot of osmotic pressure ($\mathrm{\pi }$) versus the concentration (c in mol L^-1) gives a straight line with slope 310R where 'R' is the gas constant. The temperature at which osmotic pressure measured is -

1. 310 × 0.082 K

2. 310${}^{\mathrm{o}}$C

3. 37${}^{\mathrm{o}}$C

4. $\frac{310}{0.082}K$

For the dissociation of PCl₅ into PCl₃ and Cl₂ in gaseous phase reaction, if d is the observed vapour density and D the theoretical vapour density with 'a' as degree of dissociation. Variation of D/d with 'a' is given by which graph

1. 

2. 

3. 

4. Any of these

At $100°\mathrm{C}$ the vapour density of nitrogen peroxide (N₂O₄) is 26.8. The percentage dissociation into NO₂ molecules is

1. 71.64%

2. 61.57%

3. 83.56%

4. 67.39%

The vapour density of N₂O₄ at a certain temperature is 30. What is the percentage dissociation of N₂O₄ at this temperature?

1. 53.3

2. 106.6

3. 26.7

4. none of these

What is the correct sequence of active masses in increasing order in gaseous mixture, containing one gram per litre of each of the following?

I. NH₃

II. N₂

III. H₂

IV. O₂

Select the correct answer using the codes given below:

1. III, I, IV, II

2. III, IV, II, I

3. II, I, IV, III

4. IV, II, I, III

17.4 % (w/v) ${\mathrm{K}}_2{\mathrm{SO}}_4$ solution at 27 $°$C is isotonic to 5.85 % (w/V) NaCl solution at 27 $°$C. lf NaCl is 100 % ionised, the % ionisation of ${\mathrm{K}}_2{\mathrm{SO}}_4$ in aqueous solution is-

[At wt. of K = 39, Na = 23] :-

1. 25 %

2. 75 %

3. 50 %

4. None of the above

Heating a saturated sodium chloride solution leads to:

1. Saturation being maintained

2. The solution becomes unsaturated

3. Solution becoming supersaturated

4. The system reaching an equilibrium point