Calculate the volume occupied by 7g of nitrogen gas at 27°C  and 750 mm of Hg

Convert the given data into required units of ideal gas equation.

$\mathrm{n}=\frac{7\mathrm{g}}{28\mathrm{g}/\mathrm{mol}}=\frac{1}{4}\mathrm{mol};\mathrm{T}=27+273=-300\mathrm{k}$

$\mathrm{P}=\frac{750}{760}\mathrm{atm} \left[1 \mathrm{atm}= 760 \mathrm{mm} \mathrm{of} \mathrm{Hg}\right]$

The ideal gas equation is

$\mathrm{PV}=\mathrm{nRT}$

Then $\mathrm{V}=\frac{\mathrm{nRT}}{\mathrm{P}}\to \mathrm{eqn}\left(1\right)$

Put the above values in the equation (1)

$\mathrm{v}=\frac{\frac{1}{4}\times 0.0821\times 300\times 760}{750}$

=6.24 lit

The volume occupied by 7g of Nitrogen gas at 27°C and 750mm of Hg pressure is 6.24  lit.