Calculate the C-C bond energy from the following data : (i) 2 C ( graphite )+3H_(2)(g) rarr C_(2)H_(6)(g), DeltaH =- 84.67 kJ (ii) C ( graphite ) rarr C(g), Delta H = 716 .7 kJ (iii) H_(2)(g) rarr 2H(g), Delta H = 435.9 kJ Assume the C-H bond energy as 416 kJ

Calculate the C-C bond energy from the following data : (i) 2 C ( grap

1.	Calculate the C-C bond energy from the following data : (i) 2 C ( graphite )+3H_(2)(g) rarr C_(2)H_(6)(g), DeltaH =- 84.67 kJ (ii) C ( graphite ) rarr C(g), Delta H = 716 .7 kJ (iii) H_(2)(g) rarr 2H(g), Delta H = 435.9 kJ Assume the C-H bond energy as 416 kJ
Answer» Solution :Let us calculate `DeltaH` for the reaction,`C_(2)H_(6)(g),i.e., H - underset(H) underset(\|) overset(H) overset(\|) (C)-underset(H) underset(\|) overset(H) overset(\|) (C) -H(g) RARR 2C(g) +6H(g)` ` 2 xx `EQN. (ii) `+3 xx ` Eqn. (iii) -Eqn. (i) GIVES `Delta _(r)H= 2825.77 kJ` Ifx is the bond energy of C-C bond,then `x+ 6 B.E. ( C-H)= 2825.77` `x +6 ( 416) = 2825.77` or `x=329.77kJ`