Question

Heat of neutralisation of $NaOH$ with equivalent amount of acid is maximum in case of:

• A. $HI$
• B. $HCl$
• C. $HBr$
• D. $HF$

Answer 1

The correct option is D $HF$

Solution:- (D) $HF$

Dissociation of $HX$-

$HX⟶H^{+}+X^{-}$

Since size of $F^{-}$ is small, thus it is extensively hydrated which releases large amount of energy which account for its higher neutralization enthalpy.

Hence heat of neutralization of $NaOH$ is maximum in case of $HF$.