# Question #94985

May 19, 2014

To solve this problem we would use the combined gas law.

The formula for the combined gas law is
$\frac{\left({P}_{i}\right) \left({V}_{i}\right)}{T} _ i = \frac{\left({P}_{f}\right) \left({V}_{f}\right)}{T} _ f$

We begin by identifying the values for each of the variables and identifying the missing value.

${P}_{i}$ = 715 torr
${V}_{i}$ = 250. mL
${T}_{i}$ = 35 C + 273 = 308 K

${P}_{f}$ = 925 torr
${V}_{f}$ = ???
${T}_{f}$ = 85 C + 273 = 358 K

Remember to always convert Celsius to Kelvin for the gas laws.
$C + 273 = K$

$\frac{\left(715 t r r\right) \left(250. m L\right)}{308 K} = \frac{\left(925 t r r\right) \left(x\right)}{358 K}$

$\frac{\left(358 K\right) \left(715 t r r\right) \left(250. m L\right)}{\left(308 K\right) \left(925 t r r\right)} = \left(x L\right)$

$x L = 225 m L$