Question

Find ΔG∘rxn for the reaction 2A+B→2C from the given data.

A→B	ΔG∘rxn=100 kJ
C→2B	ΔG∘rxn=432 kJ
A→C	ΔG∘rxn=−187 kJ

Answer 1

A B   = 100 kJ   ------------------- equation (1)

C 2B   = 432 kJ

or, 2B C = - 432 kJ ------------------- equation (2)

A C = −187 kJ   ------------------- equation (3)

Adding equation (1), equation (2) and equation (3) we get,

2A + 2B 2C + B      = (100 - 432 - 187) kJ

or, 2A + B 2C         = - 519 kJ

Therefore for 2A + B 2C reaction, = - 519 kJ.