Answer
$$P = 1.16 \space atm $$
Work Step by Step
1. According to the Ideal Gas Law:
$$P = \frac{nRT}{V} = \frac{( 0.448 \space mol)( 0.08206 \space atm \space L \space mol^{-1} \space K^{-1} )( 315 \space K)}{ 10.0 \space L }$$
$$P = 1.16 \space atm $$
