The balanced reaction that describes the reaction between hydrogen and nitrogen to produce ammonia is expressed 3H2 + N2 = 2NH3. The yield of the reaction is equal to the actual amount of product divided to the theoretical amount of product multiplied by 100 percent. 26.3 grams of H2 theoretically produces149 grams. The yield is 79 divided by 149 equal to 53.02 percent.