Calculate the enthalpy of hydrogenation of ethylene from the following data. Bond energies of C-H , C-C , C=C and H-H are 414,347,618 and 435 kJ mol^(-1) .

Calculate the enthalpy of hydrogenation of ethylene from the following

1.	Calculate the enthalpy of hydrogenation of ethylene from the following data. Bond energies of C-H , C-C , C=C and H-H are 414,347,618 and 435 kJ mol^(-1) .
Answer» Solution :Given : `E_(C-H)=414 "kJ mol"^(-1)` `E_(C-C)=347 "kJ mol"^(-1)` `E_(C=C)=618 "kJ mol"^(-1)` `E_(H-H)=435 "kJ mol"^(-1)` `DeltaH_r=SUM "(Bond energy)"_r -sum "(Bond energy)"_p` `DeltaH_r=(E_(C=C)+4E_(C-H)+E_(H-H))-(E_(C-C) +6E_(C-H))` `DeltaH_r` = (618 + ( 4 x 414 ) + 435 ) -(347 +(6 x 414)) `DeltaH_r`=2709-2831 `DeltaH_r=-122 "kJ mol"^(-1)`