Ammonia gas combines with excess oxygen gas to produce nitric oxide and water. How many grams of ammonia gas would have to react in order to release 154 kJ of energy

11.6g of NH₃ (g) have to react

Explanation:

For the reaction:

4 NH₃ (g) + 5 O₂ (g) → 4 NO (g) + 6 H₂O (g) ΔH = - 905kJ

4 moles of ammonia produce 905kJ

Thus, if you want to produce 154kJ of energy you need:

154kJ * (4 mol NH₃ / 905kJ) = 0.681moles of NH₃. In mass - Molar mass ammonia is 17.031g/mol-

0.681mol NH₃ * (17.031g / mol) = 11.6g of NH₃ (g) have to react