Question

The value of ∆H(fusion) for NH3 is -91.8kJ per mol calculate enthalpy Change for 2NH3 (g) -----> N2 (g) + 3H2 (g)

Answer 1

del H for fusion is given, so we need del H for decomposition which is negative of the del H for fusion =-(-91.8)=91.8 per mol. Here, two moles of NH3 is decomposed which means, del H =2*91.8=183.6 kJ.