Question

At what temperature will the total K.E (Kinetic Energy) of $0.3\text{mol}$ of $\text{He}$ be the same as the total K.E (Kinetic Energy) of $0.4\text{mol}$ of $\text{Ar}$ at $400K$?

• A. $533.33K$
• B. $400K$
• C. $346K$
• D. $300K$

Answer 1

The correct option is A $533.33K$

We know total K.E. is given as:
$\frac{3}{2}nRT$
According to question,
${\left[\frac{3}{2}nRT\right]}_{He}={\left[\frac{3}{2}nRT\right]}_{Ar}$
$0.3T=0.4\times 400$
So, $T=533.33K$