Question

At what temperature will the total K.E. of 0.3 mol of $He$ be the same as the total K.E. of 0.40 mol of $Ar$ at $400\text{K}$ ?

• A. $533\text{K}$
• B. $400\text{K}$
• C. $346\text{K}$
• D. $300\text{K}$

Answer 1

The correct option is A $533\text{K}$

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, $T=533\text{K}$