Question

Enthalpy of polymerisation of ethylene, as represented by the reaction ,
`Q : N_(2)(g)+2O_(2)(g)toN_(2)O_(4)(g),DeltaH_(Q)=2.31kcal` is `-100` kJ per mole of ethylene. Given bond enthalpy of `C=C` bond is 600 kJ `mol^(-1)`, enthalpy of `C-C` bond (in kJ mol) will be :
A. 116.7
B. 350
C. 700
D. indeterminate

Answer 1

Correct Answer - B
`nCH_(2) = CH_(2) rarr (-CH_(2) - CH_(2) - )_(n)`
In thi sprocess, one mol of double bond `(C = C)` are replaced by 2 mol of single bonds `(C - C) 600 - (2 xx C - C) = -100`