Calculate the mass and volume of hydrogen that will react with nitrogen if you get 68 g of the product.

Given:

m (NH3) = 68 g

To find:

V (H2) -?

m (H2) -?

Decision:

N2 + 3H2 = 2NH3, – we solve the problem, relying on the composed reaction equation:

1) Find the amount of ammonia formed during the reaction:

n (NH3) = m: M = 68 g: 17 g / mol = 4 mol

2) We compose a logical expression:

if 3 mol H2 gives 2 mol NH3, then x mol H2 will give 4 mol NH3, then x = 4 * 3: 2 = 6 mol.

3) Find the mass of hydrogen:

m (H2) = n * M = 6 mol * 2 g / mol = 12 g

4) Find the volume of hydrogen:

V (H2) = n * Vm = 6 mol * 22.4 L / mol = 134.4 L

Answer: m (H2) = 12 g; V (H2) = 134.4 liters.