δ H for the reaction 2C(s) + 3(g) -> (g) is -20.24 kcal/mol. The bond energies (in kcal/mol) of C-C, — Thermodynamics and Thermochemistry Chemistry Question

Question

δ H for the reaction 2C(s) + 3$H_2$(g) -> $C_2H_6$(g) is -20.24 kcal/mol. The bond energies (in kcal/mol) of C-C, C-H and H-H are 63, 85.6 and 102.6, respectively. The enthalpy of sublimation of C(s) is