Question

Given, $CH_{3}COOH\left(a q\right) \rightarrow CH_{3}COO^{-}\left(a q\right)+H^{+}\left(a q\right)$

$\text{ΔH}_{\text{rxn}}^{\text{o}} \, \text{=} \, \text{0} \text{.004} \, \text{kcal} \, \text{gm}^{- \text{1}}$

Enthalpy change when $1$ mole of $Ba(OH)_{2}$ , a strong base, is completely neutralized by $CH_{3}COOH\left(\right.aq\left.\right)$ is ( $\Delta H^{^\circ }$ of neutralization of strong acid with strong base is = $- \text{13} \text{.7} \, \text{kcal} \, \text{mol}^{- \text{1}}$ )

• A. $- \text{27} \text{.46 kcal/mol}$
• B. $\text{27} \text{.46 kcal/mol}$
• C. $- \text{26} \text{.92} \, \text{kcal/mol}$
• D. $- \text{13} \text{.46 kcal/mol}$

Answer 1

Answer: (C)

$\text{ΔH}^{\text{o}}$ ionisaton of $\text{CH}_{\text{3}} \text{COOH} \, \text{=} \, \text{0} \text{.004} \, \times \, \text{60} \, \text{=} \, \text{0} \text{.24} \, \text{kcal/mol}$

$\therefore $ Enthalpy change $=\left(- 13.7 + 0.24\right)\times 2$

$\text{=} \, - \text{26} \text{.92} \, \text{kcal} \, \text{mol}^{- \text{1}}$