Question

The average speed of an ideal gas molecule at ${27}^{o}C$ is $0.3mse{c}^{-1}$. The average speed at ${927}^{o}C$ is:

• A. $0.15mse{c}^{-1}$
• B. $0.6mse{c}^{-1}$
• C. $1.2mse{c}^{-1}$
• D. $0.6cmse{c}^{-1}$

Answer 1

The correct option is B $0.6mse{c}^{-1}$

As we know,

$U_{avg}=\sqrt{\frac{8RT}{\pi M}}$

${27}^{0}C=300K$ and ${927}^{0}C=1200K$

$\frac{U_{avg}}{0.3}=\sqrt{\frac{1200}{300}}$

$U_{avg}=0.6m/sec$.

So, the correct option is $B$