Answer
-96° C
Work Step by Step
$V_{1}=2.50\,L$
$T_{1}=(80+273)K= 353\,K$
$V_{2}= 1.25\,L$
According to Charles's law,
$\frac{V_{1}}{T_{1}}=\frac{V_{2}}{T_{2}}$ (unchanging P and n)
$\implies T_{2}=\frac{V_{2}T_{1}}{V_{1}}=\frac{1.25\,L\times353\,K}{2.50\,L}$
$=177\,K=(177-273)^{\circ}C=-96^{\circ}C$
