Using the data provided, calculate the multiple bond energy `(kJ mol^(-1))` of a `C-=C` bond in `C_(2)H_(2)`. That energy is `(` take the bond energy of a `C-H` bond as `350kJ mol^(-1))`.
`2C_((s))+H_(2(g))rarr C_(2)H_(2(g)), Delta=225kJ mol^(-1)`
`2C_((s))rarr 2C_(g)), DeltaH=1410kJ mol^(-1)`
`H_(2(g)) rarr 2H_((g)),DeltaH=330kJ mol^(-1)`

Options

A. 1165
B. 837
C. 865
D. 815

Answer

D

Explanation

`DeltaH =(1410+330)-[2xx350+B.E._(C-=C)]`
`225=1740-700-B.E._(C-=C)`
`:. B.E._(C-=C)=1040-225=815 kJ mol^(-1)`