Answer : 51.8 g of nitrogen are needed to produce 100 grams of ammonia gas.
Solution : Given,
Mass of  = 100 g
 = 100 g
Molar mass of  = 27 g/mole
 = 27 g/mole
Molar mass of  = 28 g/mole
 = 28 g/mole
First we have to calculate moles of  .
.

The given balanced chemical reaction is,

From the given reaction, we conclude that
2 moles of  produced from 1 mole of
 produced from 1 mole of 
3.7 moles of  produced from
 produced from  of
 of 
Now we have to calculate the mass of  .
.
Mass of  = Moles of
 = Moles of  × Molar mass of
 × Molar mass of 
Mass of  = 1.85 mole × 28 g/mole = 51.8 g
 = 1.85 mole × 28 g/mole = 51.8 g
Therefore, 51.8 g of nitrogen are needed to produce 100 grams of ammonia gas.