How much heat will be released (∆H) if 0.4501 mol of NH₃ are mixed with 0.20 mol of O₂ in the following chemical reaction? 4 NH₃ (g) + O₂ (g) → 2 N₂H₄ (g) + 2 H₂O (g) ∆H° = -286 kJ/mol

Question

How much heat will be released (∆H) if 0.4501 mol of NH₃ are mixed with 0.20 mol of O₂ in the following chemical reaction? 4 NH₃ (g) + O₂ (g) → 2 N₂H₄ (g) + 2 H₂O (g) ∆H° = -286 kJ/mol

Answer 1

4 moles of NH3 reacts with 1 mole of O2

therefore,

0.4501 mole of NH3 should react with 0.4501 x 1 / 4 = 0.1013 moles of O2

NH3 is limiting reagent and O2 is excess reagent

4 moles of NH3 releases 286 KJ/mol of energy

0.4501 mole NH3 will release 286KJ/mol x 0.4501 / 4mol = 32.1822 KJ/mol of energy

Answer: -32.18 KJ/mol

Hope this helps :)