How many grams of hydrogen is required for the reaction with nitrogen weighing 50.4 grams.

How many grams of hydrogen is required for the reaction with nitrogen weighing 50.4 grams. if the result is ammonia NH3.

Given:
m (N2) = 50.4 g

To find:
m (H2) -?

Decision:
1) N2 + 3H2 => 2NH3;
2) n (N2) = m (N2) / Mr (N2) = 50.4 / 28 = 1.8 mol;
3) n (H2) = n (N2) * 3 = 1.8 * 3 = 5.4 mol;
4) m (H2) = n (H2) * Mr (H2) = 5.4 * 2 = 10.8 g.

Answer: The mass of H2 is 10.8 g.