Answer
a) $T_{2}$ = $T_{1}$
b) $p_{2}$ = $\frac{p_{1}}{2}$
Work Step by Step
a) This is an Isothermal process which means that temperature is constant:
$T_{2}$ = $T_{1}$
b) We can use the ideal gas law to find $p_{2}$ :
$\frac{p_{1}V_{1}}{T_{1}}$ = $\frac{p_{2}V_{2}}{T_{2}}$
Where:
$p_{1}$ is the initial pressure
$p_{2}$ is the final pressure
$T_{1}$ is the initial temperature
$T_{2}$ is the final temperature
$V_{1}$ is the initial volume
$V_{2}$ is the final volume
So:
$p_{2}$ = $\frac{p_{1}V_{1}T_{2}}{V_{2}T_{1}}$ = $\frac{p_{1}V_{1}T_{1}}{2V_{1}T_{1}}$ = $\frac{p_{1}}{2}$