To determine the standard enthalpy change of the precipitation reaction, we need to use the balanced chemical equation and the standard enthalpies of formation for each compound involved in the reaction. The balanced chemical equation for the reaction is:CuSO aq + Ca OH aq Cu OH s + CaSO s + HO l Now, we need the standard enthalpies of formation Hf for each compound. The values are usually given in kJ/mol and can be found in tables or online resources. Here are the values for the compounds involved in this reaction:Hf [CuSO aq ] = -769.98 kJ/molHf [Ca OH aq ] = -944.7 kJ/molHf [Cu OH s ] = -1004.2 kJ/molHf [CaSO s ] = -1434.5 kJ/molHf [HO l ] = -285.83 kJ/molTo calculate the standard enthalpy change H for the reaction, we can use the following equation:H = [Hf products ] - [Hf reactants ]H = [Hf Cu OH + Hf CaSO + Hf HO ] - [Hf CuSO + Hf Ca OH ]H = -1004.2 kJ/mol + -1434.5 kJ/mol + -285.83 kJ/mol - -769.98 kJ/mol + -944.7 kJ/mol H = -2724.53 kJ/mol - -1714.68 kJ/mol H = -1009.85 kJ/molSo, the standard enthalpy change of the precipitation reaction between aqueous solutions of copper II sulfate and calcium hydroxide is -1009.85 kJ/mol.