Answer
$E_{internal}=3.4KJ$
Work Step by Step
The internal energy of gas can be calculated as
$E_{interanl}=\frac{3}{2}nRT$
The data in the question stipulates that $n=1$ and $T=273$. We already know that $R=8.314$.
Substituting these values in the formula:
$E_{internal}=\frac{3}{2}(1)(8.314)(273)=3.4\times10^3J$
$E_{internal}=3.4KJ$
