question_answer

From the following bond energies:                                                  [AIPMT (S) 2009]

\[H-H\] bond energy: 431.37 kJ \[mo{{l}^{-1}}\]

\[C=O\] bond energy: 606.10 kJ \[mo{{l}^{-1}}\]

\[C-C\] bond energy: 336.49 kJ \[mo{{l}^{-1}}\]

\[C-H\] bond energy: 410.50 kJ  \[mo{{l}^{-1}}\]

Enthalpy for the reaction,

\[\underset{\begin{smallmatrix}  | \\  H \end{smallmatrix}}{\overset{\begin{smallmatrix}  H \\  | \end{smallmatrix}}{\mathop{C}}}\,=\underset{\begin{smallmatrix}  | \\  H \end{smallmatrix}}{\overset{\begin{smallmatrix}  H \\  | \end{smallmatrix}}{\mathop{C}}}\,+H-\xrightarrow{{}}H-\underset{\begin{smallmatrix}  | \\  H \end{smallmatrix}}{\overset{\begin{smallmatrix}  H \\  | \end{smallmatrix}}{\mathop{C}}}\,-\underset{\begin{smallmatrix}  | \\  H \end{smallmatrix}}{\overset{\begin{smallmatrix}  H \\  | \end{smallmatrix}}{\mathop{C}}}\,-H\] will be

A)  \[1523.6\,kJ\,mo{{l}^{-1}}\]

B)       \[-243.6\,kJ\,mo{{l}^{-1}}\]

C)  \[-120.0\,kJ\,mo{{l}^{-1}}\]

D)       \[553.0\,kJ\,mo{{l}^{-1}}\]

Correct Answer: C

Solution :

Key Idea, Enthalpy of reaction

For reaction,