Answer
The volume occupied by 2.50 moles of $N_2$ gas is equal to 56.0 L.
Work Step by Step
1. Setup the conversion factors:
For a gas at STP conditions, we can use the equality: $1 \space mole = 22.4 \space L$:
$\frac{1 \space mole}{22.4 \space L}$ and $\frac{22.4 \space L}{1 \space mole}$
2. Calculate the volume of that sample:
$2.50 \space moles \times \frac{22.4 \space L}{1 \space mole} = 56.0 \space L$