Answer
$\Delta m=71g$
Work Step by Step
From the ideal gas equation,
$PV=nRT$
The above equation can be rearranged as:
$n=\frac{PV}{RT}$
We write the equation for the final state as:
$n{\prime}=\frac{P{\prime}V}{RT{\prime}}$
Putting the values into the above equation and solving:
$n{\prime}=\frac{(8.7\times10^5)(3.8\times10^{-2})}{(8.314)(295)}=13.5 mol$
Now, we find the amount of gas that has escaped:
$\Delta m=300 g-13.5mol(17\frac{g}{mol})$
$\Delta m=71g$
