To calculate the standard enthalpy change for the reaction between copper II sulfate pentahydrate and ammonia to form the deep blue complex ion Cu NH3 4 H2O 2SO4, we need to use Hess's Law. Hess's Law states that the total enthalpy change for a reaction is the sum of the enthalpy changes for each step in the reaction.First, let's write down the balanced chemical equation for the reaction:CuSO45H2O s + 4NH3 aq Cu NH3 4 H2O 2SO4 aq + 3H2O l Now, we need to find the standard enthalpy changes for each step in the reaction. Unfortunately, the direct enthalpy change for this reaction is not readily available in standard reference materials. However, we can use the enthalpy changes of formation for the reactants and products to calculate the overall enthalpy change for the reaction.The standard enthalpy change for a reaction H can be calculated using the following equation:H = Hf products - Hf reactants where Hf is the standard enthalpy of formation for each substance.We need to find the standard enthalpy of formation for each substance involved in the reaction:1. CuSO45H2O s : -1541 kJ/mol2. NH3 aq : -80.29 kJ/mol3. Cu NH3 4 H2O 2SO4 aq : This value is not readily available, so we will need to find a way to calculate it.4. H2O l : -285.8 kJ/molSince we don't have the standard enthalpy of formation for Cu NH3 4 H2O 2SO4 aq directly, we can use the enthalpy changes of other reactions involving the formation of this complex ion. One such reaction is the formation of the complex ion from CuSO4 aq and NH3 aq :CuSO4 aq + 4NH3 aq Cu NH3 4SO4 aq We can find the enthalpy change for this reaction H1 from reference materials:H1 = -49.5 kJ/molNow, we can use this reaction and the enthalpy change for the dissolution of CuSO45H2O s in water to form CuSO4 aq to calculate the enthalpy change for the overall reaction. The enthalpy change for the dissolution of CuSO45H2O s H2 is:H2 = -64.4 kJ/molUsing Hess's Law, we can calculate the enthalpy change for the overall reaction H :H = H1 + H2H = -49.5 kJ/mol + -64.4 kJ/mol H = -113.9 kJ/molTherefore, the standard enthalpy change for the reaction between copper II sulfate pentahydrate and ammonia to form the deep blue complex ion Cu NH3 4 H2O 2SO4 is -113.9 kJ/mol.