Question

The enthalpy of neutralization for all strong acid - strong base reactions should be the same, within experimental error. True or false? Explain

Answer 1

Yes ,The enthalpy of neutralization of strong acid- strong base reaction should be same within the experimental error.

Any neutralisation reaction between strong acid and strong alkali( base) actually comes down to the same thing i.e. H+ + OH- = H2O, as all the other ions present are spectator ions and so don't play an active part in the reaction. As the overall reaction is always the same irrespective of the acid or alkali the enthalpy change will also be the same.

If a weak acid is used the enthalpy change will be less exothermic as some of the energy evolved will be cancelled out by the energy needed to complete the dissociation of the incompletely dissociated acid during the reaction