Question

Calculate the enthalpy for the reaction D + F = G + H using

G + C = A + B deltaH = 277
C + F = A delta H = 303
D = B + H delta H = -158​

Answer 1

The enthalpy for the reaction : ΔH = -132

Further explanation

Given

Reaction and the enthalpy

Required

the enthalpy

Solution

Hess Law

Reaction 1 reverse :

A + B = G + C ΔH = -277

Reactions 2 and 3 remain the same (unchanged)

C + F = A ΔH = 303

D = B + H ΔH = -158

Add up all the reactions and remove the same compound from two different sides

D + F = G + H ΔH = -132