Al + CuSO4 = Cu + Al2(SO4)3

Al (aluminum) + CuSO_4 (copper(II) sulfate) ⟶ Cu (copper) + Al_2(SO_4)_3 (aluminum sulfate)

Balance the chemical equation algebraically: Al + CuSO_4 ⟶ Cu + Al_2(SO_4)_3 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Al + c_2 CuSO_4 ⟶ c_3 Cu + c_4 Al_2(SO_4)_3 Set the number of atoms in the reactants equal to the number of atoms in the products for Al, Cu, O and S: Al: | c_1 = 2 c_4 Cu: | c_2 = c_3 O: | 4 c_2 = 12 c_4 S: | c_2 = 3 c_4 Since the coefficients are relative quantities and underdetermined, choose a coefficient to set arbitrarily. To keep the coefficients small, the arbitrary value is ordinarily one. For instance, set c_4 = 1 and solve the system of equations for the remaining coefficients: c_1 = 2 c_2 = 3 c_3 = 3 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 Al + 3 CuSO_4 ⟶ 3 Cu + Al_2(SO_4)_3