Question

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

Answer 1

Correct Answer - D
In the reaction
`2C(s)+H-HtoH-C-=C-H," "DeltaH=225kJ" "mol^(-1)`
`DeltaH=sum` Bond energy of reactants-`sum` Bond energy of products
`225=[1410+330]-[700+be" of "C-=C]`
`BE(C-=C)=815kJ//mol`