The volume occupied by 7 grams of nitrogen gas at STP is:

The correct option is A 5.6 l
No of mole of nitrogen $=\frac{7}{28}=\frac{1}{4}$ mole
As we know, one mole occupies 22.4 litre volume, so $\frac{1}{4}$ mole will occupy, $V=\frac{22.4}{4}=5.6litre$.