Acetic acid `(` ethanoic acid `)` and hydrochloric acid react with `KOH` solution. The enthalpy of neutralisation of ethanoic acis is `-55.8kJ mol^(-1)` while that of hydrochloric acid is `-57.3kJ mol^(-1)` . Can you think of how are these different?`

Explanation

Enthalpy of neutralisation for `HCl=-57.3 kJ mol^(-1)`
Enthalpy of neutralisation for `CH_(3)COOH=-55.8kJ mol^(-1)`
In case of neutralisation of `CH_(3)COOH,` the part of heat released `[-57.3-(-55.8)=-1.5kJ]` is used up in dissociation of acetic acid and thus heat given out is lesser than `57.3kJ`.