The neutralization reaction between hydrochloric acid HCl and sodium hydroxide NaOH can be represented by the following balanced chemical equation:HCl aq + NaOH aq NaCl aq + H2O l The standard enthalpy change of this reaction, also known as the enthalpy of neutralization, is the amount of heat released when one mole of an acid reacts with one mole of a base under standard conditions 25C and 1 atm . For strong acids and strong bases, like HCl and NaOH, the enthalpy of neutralization is relatively constant, with a value of approximately -55.9 kJ/mol.So, the standard enthalpy change for the neutralization reaction between hydrochloric acid and sodium hydroxide under the given conditions is approximately -55.9 kJ/mol.