Answer
5.39 L
Work Step by Step
$P_{1}=785\, mmHg$
$V_{1}=4.80\,L$
$T_{1}=(18+273)K=291\,K$
$P_{2}= 745\, mmHg$
$T_{2}=(37+273)K=310\,K$
According to combined gas law,
$\frac{P_{1}V_{1}}{T_{1}}=\frac{P_{2}V_{2}}{T_{2}}$ (n is constant)
$\implies V_{2}=\frac{P_{1}V_{1}T_{2}}{T_{1}P_{2}}=\frac{785\, mmHg\times4.80\,L\times310\,K}{291\,K\times745\, mmHg}$
$=5.39\,L$
