How many grams of H2 are needed to produce 13.26 g of NH3? Express your answer numerically in grams.

Answer 1

Balanced chemical equation is:

3H₂ + N₂ → 2NH₃

The dimensional analysis and stoichiometry are:

13.26 g NH₃ x (1 mol NH₃/17 g NH₃) x (3 mol H₂/2 mol NH₃) x (2 g H₂/1 mol H₂) =

2.34 g H₂

Answer 2

First, balance the equation

2N2 + 3H2 ==> 2NH3

One mole of NH3 has a mass of 17 grams. (14+1+1+1). 13.26 grams of NH3 is thus13.26/17 = 0.78 moles of NH3

Using the more ratio, 2 moles of NH3 require 3 moles of H2. So, 0.78 moles of NH3 use 0.78*2/3 = 0.52 moles of H2

One mole of H2 is 2 gram, so you need 0.52 * 2 = 1.04 grams of H2