Question

calculate

(a) the standard enthalpy, (

b) the standard Gibbs energy, of the reaction

4NO2(g) + O2(g) → 2N2O5(g)

Answer 1

Solution :-

4NO2(g) + O2(g) → 2N2O5(g)

Formula to calculate the standard enthalpy change of the reaction is

Delta H rxn = sum of delta H product – sum of delta H reactant

                    = [N2O5*2] –[ (NO2*4)+(O2*1)]

                    = [11*2]-[(33.2*4)+(0*1)]

                   = -110.8 kJ

Now lets calculate the free energy of the reaction

Delta Grxn = sum of delta G product – sum of delta G reactant

                    = [N2O5*2] –[ (NO2*4)+(O2*1)]

                    = [118*2]-[(51*4)+(0*1)]

                    = 32 kJ