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

An open flask contining air is heated from 300 K to 500 K. What percentage of air will be escaped to the atmosphere, if pressure is keeping constant?

1. 80

2. 40

3. 60

4. 20

Four particles have velocities 1, 0, 2, 3 m/s. The root mean square of the particles is (in m/s)

(A) $3.5$                                

(B) $\sqrt{3.5}$

(C) $1.5$                                

(D) $\sqrt{14/3}$

At high pressure, Van der Waal’s equation
becomes

1. PV = RT

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

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

4. PV = RT+Pb

A gas describe by Van der Waal’s equation,
incorrect statement is..

1. behaves similar to an ideal gas in the limit of
large molar volumes.

2. behaves similar to an real gas in the limit of
large volumes.

3. is characterized by van der Waals’ coefficients
that are dependent on the identity of the gas but
are independent of the temperature.

4. has the pressure that is lower than the pressure
exerted by the same gas behaving ideally

If for two gases of molecular weights M_A and M_B at temperature T_A and T_B, T_AM_B = T_BM_A, then which property has the same magnitude for both the gases?

1. Density

2. Pressure

3. KE per mol

4. Vrms

Boyle’s law may be expressed as

1. ${\left(\frac{\mathrm{dP}}{\mathrm{dV}}\right)}_T=\frac{K}{V}$

2. ${\left(\frac{\mathrm{dP}}{\mathrm{dV}}\right)}_T=\frac{K}{V^{\mathit{2}}}$

3. ${\left(\frac{\mathrm{dP}}{\mathrm{dV}}\right)}_T=-\frac{K}{V}$

4. None

Which set of conditions represents easiest way
of liquify a gas?
1. Low temperature and high pressure
2. High temperature and low pressure
3. Low temperature and low pressure
4. High temperature and high pressure

A sample of air contains only N₂, O₂ and H₂O. It
is saturated with water vapours and the total
pressure of 640 torr. The vapour pressure of
water is 40 torr and the molar ratio of N₂: O₂
is 3 : 1. The partial pressure of N2
in the sample in

1. 480 torr

2. 600 torr

3. 525 torr

4. 450 torr