Question

At what temperature will the molar kinetic energy of 0.3 mol of helium be the same as that of 0.4 mol of argon at 400 K?

• A. 700 K
• B. 533 K
• C. 800 K
• D. 400 K

Answer 1

The correct option is B 533 K

As we know, $KE=\frac{3}{2}nRT$
$n=1$, for molar kinetic energy
${[\frac{3}{2}\times 0.3\times R\times T]}_{Helium}={[\frac{3}{2}\times 0.4\times R\times 400]}_{Argon}$
$T=533K$