The dissociation energy of CH4 is 360 kcal / mol and of ethane is 620 kcal / mol. Calculate C-C bond energy. (in kCal)

Given, CH4→C+4H; ΔH=360kcal∴ Bond energy of 4(C−H) bond =360kcal∴ Bond energy of C−H bond =3604=90kcal In C2H6→2C+6H  Bond energy of C2H6=1(C−C)+6(C−H)620=1(C−C)+6×90C−C=620−540=80kcal∴ Bond energy of C−C=80kcal