Question

Ammonia reacts with oxygen according to the equation: 4NH3(g)+5O2(g)→4NO(g)+6H2O(g)ΔHrxn=−906kJ. Calculate the heat (in kJ) associated with the complete reaction of 215 g of NH3.

Answer 1

4NH₃(g)+5O₂(g)→4NO(g)+6H₂O(g)        ΔHrxn=−906kJ.

negative values of ΔH indicate exothermic reactions. MW of ammonia is 17.

4 moles of NH₃ on combustion produce 906 kl heat

68 gms (4x17) of NH₃ on combustion produce 906 kl heat

215 gms of NH₃ on combustion produce -------- kj heat

                                                           =(906/68)x 215= 2864.6 kj