Question

Which of the following statements is TRUE?

Answer 1

Answer:

The correct option is E.

Explanation:

Average speed of the gas molecules = $v_a$

$v_a=\sqrt{\frac{2RT}{M}}$

T = Temperature of the gas molecule

M = molar mass of gas molecule

R = gas constant

$v_a\propto \frac{1}{M}$

Higher the molar mass of the molecule lesser will be the speed and vice versa.

Hence, statement A is not true.

Graham's Law.

This law states that the rate of effusion or diffusion of gas is inversely proportional to the square root of the molar mass of the gas. The equation given by this law follows the equation:

$\text{Rate of diffusion}\propto \frac{1}{\sqrt{\text{Molar mass of the gas}}}$

Larger the molar mass that larger the molecule lessor will be the effusion and vice versa.

Hence, statement B is not true.

According to Boyle's law, pressure of the gas is inversely proportional o the volume occupied by the gas at constant temperature. And same can also be observed from ideal gas law:

$PV=nRT$

$P=\frac{nRT}{V}$

$P\propto \frac{1}{V}$

Higher the pressure of the gas lower will be the volume occupied by the gas and vice versa.

Hence, statement C is not true.

With rise in temperature, effusion of gas molecule increase as kinetic energy of gas molecules increases in with increase in temperature.

Average kinetic energy is defined as the average of the kinetic energies of all the particles present in a system. It is determined by the equation:

$K=\frac{3RT}{2N_A}$

where,

K = Average kinetic energy

R = Gas constant

T = Temperature of the system

$N_A$ = Avogadro's number

$K\propto T$

Higher the temperature more will be kinetic energy of gas molecule more easily it will effuse.

Hence, statement D is not true.

From this we can conclude that out of five statements first 4 statements are not true which means that none of these statements are true.