For one mole of van der Waal's gas when b=0 and T=300 K, the PV vs. 1/V plot is shown below.

The value of the van der Waal's constant 'a' (atm. ${\mathrm{litre}}^2$ ${\mathrm{mol}}^{-2}$) is-

 

1. 1.0

2. 4.5

3. 1.5

4. 3.0

At 298 K, assuming ideal behaviour, the average kinetic energy of a deuterium molecule is -

1. Two times that of a hydrogen molecule

2. Four times that of a hydrogen molecule

3. Half of that of a hydrogen molecule

4. Same as that of a hydrogen molecule

At room temperature, the average speed of Helium is higher than that of Oxygen by a factor of -

1. $2\sqrt{2}$

2. $6/\sqrt{2}$

3. 8

4. 6

In water-saturated air, the mole fraction of water vapor is 0.02. If the total pressure of the saturated air is 1.2 atm, the partial pressure of dry air is-

1. 1.17 atm

2. 1.76 atm

3. 1.27 atm

4.  0.98 atm

The volume occupied by 1.8 g of water vapour at 374 ${}^{\mathrm{o}}\mathrm{C}$ and 1 bar pressure will be -

[Use R=0.083 bar ${\mathrm{LK}}^{-1}$ ${\mathrm{mol}}^{-1}$]

1. 96.66 L

2. 55.87 L

3. 3.10 L

4. 5.31 L

Van der Waals equation at low pressure is -

1. PV = RT - Pb

2. PV = RT - $\frac{\mathrm{a}}{\mathrm{V}}$

3. PV = RT + $\frac{\mathrm{a}}{\mathrm{v}}$

4. PV = RT + Pb

The density of a gaseous substance at 1 atm pressure and 773 K is 0.4 g/L. If the molecular weight of the substance is 30, the dominant force existing among gas molecules is/are-

1. Repulsive

2. Attractive

3. Both (1) & (2)

4. None of these

The unit of van der Waals' constant 'b' is -

1. cm³ mol^-1

2. litre mol^-1

3. m³ mol^-1

4. All of the above

The compressibility factor for H₂ and He is usually-

1. >1                                     

2. =1

3. <1                                     

4.  Zero

In which case is the rate of diffusion highest if all are present in the same container at the same temperature:

1. 4 g H₂

2. 32 g O₂

3. 22 g CO₂

4. 56 g N₂