Question

What will be $\Delta H$ for the reaction,
$CH_2Cl_2 \to C + 2H + 2Cl ?$
$(B.E.$ of $C — H$ and $C — Cl$ bonds are $416\, kJ\, mol^{-1}$ and $325 \,kJ\, mol^{-1}$ respectively)

• A. $832\, kJ$
• B. $1482\, kJ$
• C. $650\, kJ$
• D. $1855\, kJ$

Answer 1

Answer: (B)

$\Delta H = \Sigma\,B.E._{R} - \Sigma \,B.E._{P}$
$=2\times B.E.\,\left(C — H\right) + 2 \times B.E. \,\left(C — Cl\right)$
$= 2 \times 416 + 2 \times 325 = 1482 \,kJ$