To calculate the standard enthalpy change for the reaction between hydrochloric acid HCl and potassium hydroxide KOH to produce potassium chloride KCl and water H2O , we can use the given heat of neutralization for the reaction between hydrochloric acid and sodium hydroxide NaOH .The balanced chemical equation for the reaction between HCl and KOH is:HCl aq + KOH aq KCl aq + H2O l The balanced chemical equation for the reaction between HCl and NaOH is:HCl aq + NaOH aq NaCl aq + H2O l The heat of neutralization for the reaction between HCl and NaOH is given as -57.1 kJ/mol. Since both reactions involve the same reactants strong acid and strong base and produce the same products salt and water , we can assume that the heat of neutralization for the reaction between HCl and KOH is also -57.1 kJ/mol.Therefore, the standard enthalpy change for the reaction between hydrochloric acid and potassium hydroxide to produce potassium chloride and water is -57.1 kJ/mol.