To calculate the standard enthalpy change for the reaction, we need to know the standard enthalpies of formation Hf for each compound involved in the reaction. The balanced chemical equation for the reaction is:ZnO s + 2HCl s ZnCl2 s + H2O s Now, we need the standard enthalpies of formation for each compound:Hf ZnO = -348.0 kJ/molHf HCl = -92.3 kJ/molHf ZnCl2 = -415.1 kJ/molHf H2O = -291.8 kJ/molUsing Hess's Law, we can calculate the standard enthalpy change for the reaction Hrxn as follows:Hrxn = [Hf products - Hf reactants ]Hrxn = [1 * -415.1 + 1 * -291.8 ] - [1 * -348.0 + 2 * -92.3 ]Hrxn = -415.1 - 291.8 - -348.0 - 184.6 Hrxn = -706.9 - -532.6 Hrxn = -174.3 kJ/molThe standard enthalpy change for the reaction of zinc oxide and hydrochloric acid to form zinc chloride and water, given that all reactants and products are solids at standard temperature and pressure, is -174.3 kJ/mol.