The enthalpy of atomisation for the reaction CH4(g)→C(g)+4H(g) is1665 kJ mol−1. What is the bond energy of C—H bond?
In CH4, there are four C - H bonds. The enthalpy of atomisation of 1 mole of CH4 means dissociation of four moles of C—H bond.
∴ C- H bond energy per mol =1665 kJ4 mol
=416.25 kJ mol−1