Question

In a mixture of nitrogen and helium kept at room temperature. As compared to a helium molecule hits he the wall

• A. With grater average speed
• B. with smaller average speed
• C. with grater average kinetic energy
• D. with smaller average kinetic energy

Answer 1

The correct option is B with smaller average speed

Kinetic energy is given by $E=3kT$ so it will be same for both gases because temperature and Boltzman's constant

both are same for both gases.

But the Average speed is given by $V_a=\sqrt[2]{2\frac{8RT}{\pi M}}$

Molar mass $M$ is less for helium so average speed will be $high$ for $helium$ and $smaller$ for $Nitrogen$.

Option B is correct.