Question

If heat of dissociation of $CHC{l}_{2}COOH$ is $0.7kcal/mole$ then $\Delta H$ for the reaction:

$CHC{l}_{2}COOH+KOH\to CHC{l}_{2}COOK+H_{2}O$

• A. -13 kcal
• B. +13 kcal
• C. -14.4 kcal
• D. -13.7 kcal

Answer 1

The correct option is A

-13 kcal

$H^{+}+O{H}^{-}\to H_{2}O\left(l\right)$

$\Delta H=-13.7kcal$........(i)

$CHC{l}_{2}COOH\to CHC{l}_{2}CO{O}^{-}+H^{+}$

$\Delta H=0.7kcal$........(ii)

$CHC{l}_{2}COOH+O{H}^{-}\to CHC{l}_{2}CO{O}^{-}+H_{2}O\left(l\right)$

$\Delta H$ = ?

Adding equation (i) and (ii) $\Delta H$ = = $13Kcal$.