question_answer

If at \[298\,\,K\] the bond energies of \[C-H,\,\,C-C,\]\[C=C\] and \[H-H\] bonds are respectively \[414,\,\,347,\,\,615\] and \[435\,\,kJ\,\,mo{{l}^{-1}}\], the value of enthalpy change for the reaction \[{{H}_{2}}C=C{{H}_{2}}(g)+{{H}_{2}}(g)\xrightarrow{{}}{{H}_{2}}C-C{{H}_{2}}(g)\] at \[298\,\,K\] will be

A) \[+250\,\,kJ\]                   

B)        \[-250\,\,kJ\]

C)        \[+125\,\,kJ\]                   

D)        \[-125\,\,kJ\]