The reaction between copper II sulfate pentahydrate CuSO45H2O and iron Fe can be represented by the following unbalanced chemical equation:CuSO45H2O + Fe FeSO4 + Cu + 5H2OTo balance the chemical equation, we need to make sure that the number of atoms of each element on both sides of the equation is equal. The balanced chemical equation is:CuSO45H2O + Fe FeSO4 + Cu + 5H2ONow, we need to determine how many moles of iron are needed to completely react with 5 moles of copper II sulfate pentahydrate. According to the balanced chemical equation, 1 mole of CuSO45H2O reacts with 1 mole of Fe. Therefore, 5 moles of CuSO45H2O will react with 5 moles of Fe.So, 5 moles of iron are needed to completely react with 5 moles of copper II sulfate pentahydrate.