Bond dissociation energy of `CH_(4)` is 360 kJ/mol and `C_(2)H_(6)` is 620 kJ/mol. Then bond dissociation energy of C-C bond is-

Options

A. 170 kJ/mol
B. 50kJ/mol
C. 80kJ/mol
D. 220kJ/mol

Answer

C

Explanation

Dissociation energy of methane=360`kJ*mol^(-1)`
`therefore`bond energy of C-H bond `=(360)/(4)=90kJ*mol^(-1)`
bond energy of ehane,
`1xxB.E.(C-C)+6xxB.E.(C-H)=620kJ*mol^(-1)`
or, B.E.(C-C)+6`xx90=620`
or, B.E.(C-C)+540=620
or, B.E.(C-C)=620-540
or, B.E.(C-C)=80`kJ*mol^(-1)`.