Question

Assertion :Statement-1 : The enthalpy of neutralization of the reaction between HCl and NaOH is -13.7 kCal/mol. If the enthalpy of neutralization of oxalic acid $\left(H_2{C}_2{O}_4\right)$ by a strong base is -25.4 kCal/mol, then the enthalpy change $\left(\Delta H\right)$ of the process $H_2{C}_2{O}_4\to 2H^{+}+C_2{O}_4^{2-}$ is 11.7 kCal/mol. Reason: Statement -2 : $H_2{C}_2{O}_4$ is a weak acid.

• A. Statement- 1 is true, statement -2 is true and statement-2 is correct explanation for statement -1.
• B. Statement- 1 is true, statement -2 is true and statement-2 is NOT the correct explanation for statement -1.
• C. Statement- 1 is true, statement -2 is false.
• D. Statement- 1 is false, statement -2 is true.

Answer 1

The correct option is D Statement- 1 is false, statement -2 is true.

The enthalpy of neutralization of the reaction between HCl and NaOH is -13.7 kCal/mol. If the enthalpy of neutralization of oxalic acid $\left(H_2{C}_2{O}_4\right)$ by a strong base is -25.4 kCal/mol, then the enthalpy change $\left(\Delta H\right)$ of the process $H_2{C}_2{O}_4\to 2H^{+}+C_2{O}_4^{2-}$ is $2\ast 13.7-25.4=2kCal/mol$.
Also as its neutralisation energy is less than 13.7 so its a weak acid.