#### Answer

The final volume of the gas is 6.8 L

#### Work Step by Step

Avagadro's law defines the relationship between the number of moles and volume. According to this, the volume of gas is directly proportional to the number of moles.
$\frac{V}{n} = constant $
Therefore as the number of moles of a gas increases the volume of the gas increases and as the number of moles of a gas decreases the volume of the gas decreases when it is at a constant temperature and pressure.
For a gas, we can create two equations with $V_{1}$ as the initial volume of the gas and $V_{2}$ as the final volume of the gas.
$\frac{V_{1}}{n_{1}} = \frac{V_{2}}{n_{2}}$
rearrange the equation for $V_{2}$
$V_{2} = \frac{n_{2}V_{1}}{n_{1}}$
Plug in the values for the variables
$V_{2} = \frac{2.55 L \times 0.32 mol}{0.12 mol}$
Solve using a calculator
$V_{2} = 6.8 L$