How to calculate the average quadratic velocity of carbon dioxide from given data?
Use the Ideal Gas Law: $PV=nRT \to T = \frac{PV}{nR}$.  From the mass you can find the number of moles, $n$. $P$ and $V$ are given, and $R$ is the universal gas constant.

Even better you could rearrange the equation to $RT = \frac{PV}{n}$, substitue the value for $RT$ and do less arithmatic.