At a certain temperature the time-required for the complete diffusion of 200 mL of H₂ gas is 30 min. The time required for the complete diffusion of 50 mL of O₂ gas at the same temperature will be

• 60min

• 30min

• 45min

• 15min

The RMS velocity of CO gas molecules at 27°C is approximately 1000 m/s. For N₂ molecules at 600 K, the RMS velocity is approximately

• 2000 m/s

• 1414 m/s

• 1000 m/s

• 1500 m/s

A gas can be liquefied at temperature T and pressure p provided.

• T = T_c and p < p_c

• T < T_c and p > p_c

• T > T_c and p > p_c

• T > T_c and p < p_c

The dispersed phase and dispersion medium of fog respectively are

• solid, liquid

• liquid, liquid

• liquid, gas

• gas, liquid

For the reaction,
2SO₂ (g) + O₂ (g) → 2SO₃ (g) at 300 K, the value of $∆$G° is -690.9 R. The equilibrium constant value for the reaction at that temperature is (R is gas constant)

• 10 atm^-1

• 10 atm

• 10

• 1

Four gases P, Q. R and S have almost same values of 'b' but their 'a' values (a, b are van der Waals' constants) are in the order Q < R < S < P. At a particular temperature, among the four gases, the most easily liquefiable one is

• P

• Q

• R

• S

The units of surface tension and viscosity of liquids respectively are

• kg m^-1s^-1, Nm^-1

• kg s^-2, kg m^-1s^-1

• Nm^-1, kg m^-1s^-2

• kg s^-1, kg m^-2s^-1

The compound that will have a permanent dipole moment among the following is

• I

• II

• III

• IV

The compressibility factor (Z) of one mole of a van der Waals' gas of negligible 'a' value is

• 1

• $\frac{\mathrm{bp}}{\mathrm{RT}}$

• $1+\frac{\mathrm{bp}}{\mathrm{RT}}$

• $1-\frac{\mathrm{bp}}{\mathrm{RT}}$

A van der Waals' gas may behave ideally when

• the volume is very low

• the temperature is very high

• the pressure is very low

• the temperature, pressure and volume all are very high