Answer
4.52 atm
Work Step by Step
Number of moles $n=\frac{mass\,in\,grams}{molar\,mass}= \frac{22.50\,g}{44.01\,g/mol}$
$=0.51125\,mol$
Volume $V=2.50\,L$
Temperature $T=(-4+273)K=269\,K$
$PV=nRT$ (ideal gas law) where $P$ is the pressure and $R$ is the universal gas constant.
$\implies P=\frac{nRT}{V}=\frac{(0.51125\,mol)(0.0821\,L\,atm\,mol^{-1}K^{-1})(269\,K)}{2.50\,L}$
$=4.52\,atm$
