How much heat is absorbed/released when 20.00 g of NH₃(g)reacts in the presence of excess (g)to produce NO(g)and H₂O(l)according to the following chemical equation? 4 NH₃(g)+ 5 O₂(g)→ 4 NO(g)+ 6 H₂O(l)ΔH° = 1168 kJ

Question

Quizplus · Accepted Answer

To calculate the heat absorbed or released, we need to use the given ΔH° value and the amount of NH₃ that reacted. First, we need to convert the mass of NH₃ to moles: 20.00 g NH₃ × (1 mol NH₃/112.1 g NH₃) = 0.1785 mol NH₃ According to the balanced equation, 4 moles of NH₃ react with 5 moles of O₂ to produce 1168 kJ of heat. So for 0.1785 mol NH₃: ΔH = (1168 kJ/4 mol) × 0.1785 mol = 41.44 kJ Since 4 moles of NH₃ produce heat, 0.1785 mol will absorb 41.44 kJ of heat, which is equivalent to: (41.44 kJ/0.1785 mol) × (20.00 g NH₃/1 mol NH₃) = 972.8 kJ/mol Therefore, 20.00 g of NH₃ will absorb 342.9 kJ of heat. Since the value is negative, it means the reaction is exothermic, and heat is released.

How Much Heat Is Absorbed/released When 20