H2SO4 + Al = H2 + Al2(SO4)3

H_2SO_4 (sulfuric acid) + Al (aluminum) ⟶ H_2 (hydrogen) + Al_2(SO_4)_3 (aluminum sulfate)

Balance the chemical equation algebraically: H_2SO_4 + Al ⟶ H_2 + Al_2(SO_4)_3 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_2SO_4 + c_2 Al ⟶ c_3 H_2 + 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 H, O, S and Al: H: | 2 c_1 = 2 c_3 O: | 4 c_1 = 12 c_4 S: | c_1 = 3 c_4 Al: | c_2 = 2 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 = 3 c_2 = 2 c_3 = 3 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 3 H_2SO_4 + 2 Al ⟶ 3 H_2 + Al_2(SO_4)_3