Question

With the increase in temperature of a gas, the fraction of molecules having velocities within a given range of the most probable velocity will:

• A. increase
• B. decrease
• C. remains unchanged
• D. initially increase and then decrease

Answer 1

The correct option is B decrease

According to the Maxwell Boltzmann Distribution curve, the fraction of molecule

$\frac{1}{N}\frac{dN}{du}=4\pi {\left[\frac{M}{2\pi RT}\right]}^{\frac{3}{2}}{u}^{2}exp[-\frac{m{u}^2}{2RT}]\downarrow$

Fraction of molecule

Fraction of molecule $\propto \frac{m}{T}$

So, with the increase in temperature of the gas, the fraction of molecules with velocities will decrease.