What is the Δ H of the reaction The average bond energies of C-Cl bond and C-H bond are 416 kJ and 325 ~kJ ~mol^-1 respectively.

Correct answer: (A) 1482 kJ. In the reaction, two moles of C-H bonds and two moles of C-Cl bonds are broken. Hence, energy absorbed =2 × 416+2 × 325 =1482 ~kJ

Q83 / 160 · JIPMER 2010 · Chemistry

What is the $\Delta H$ of the reaction The average bond energies of $\mathrm{C}-\mathrm{Cl}$ bond and $\mathrm{C}-\mathrm{H}$ bond are 416 kJ and $325 \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively.

Correct answer
A
1482 kJ
B
1482 J
C
1492 kJ
D
1492 J

Solution

In the reaction, two moles of $\mathrm{C}-\mathrm{H}$ bonds and two moles of $\mathrm{C}-\mathrm{Cl}$ bonds are broken. Hence, energy absorbed $\begin{aligned} & =2 \times 416+2 \times 325 \\ & =1482 \mathrm{~kJ} \end{aligned}$

Hence, the correct answer is option: 'A'.

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