Answer
The final pressure of the gas is 518 mm Hg.
Work Step by Step
The Boyle's gas law defines the relationship between pressure and volume. According to this, the volume of gas is inversely proportional to its pressure at constant temperature.
PV= constant.
Therefore as the volume of a gas increases the pressure of the gas decreases and as the volume of a gas decreases the pressure of the gas increases.
For a gas, we can create two equations with $P_{1}$ as the initial pressure of the gas and $P_{2}$ as the final pressure of the gas.
$V_{1}$= 3.95 L,
$P_{1}$= 705 mm Hg
$V_{2}$= 5.38 L.
$P_{1}$$V_{1}$ = $P_{2}$$V_{2}$
rearrange the equation for $P_{2}$
$P_{2} = \frac{P_{1}V_{1}}{V_{2}}$
Plug in the values for the variables
$P_{2} = \frac{705 mm Hg \times 3.95 L }{5.38 L}$
Solve using a calculator
$P_{2} = 518 mm Hg$