HCl + Rb = H2 + RbCl

HCl hydrogen chloride + Rb rubidium ⟶ H_2 hydrogen + RbCl rubidium chloride

Balance the chemical equation algebraically: HCl + Rb ⟶ H_2 + RbCl Add stoichiometric coefficients, c_i, to the reactants and products: c_1 HCl + c_2 Rb ⟶ c_3 H_2 + c_4 RbCl Set the number of atoms in the reactants equal to the number of atoms in the products for Cl, H and Rb: Cl: | c_1 = c_4 H: | c_1 = 2 c_3 Rb: | c_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_3 = 1 and solve the system of equations for the remaining coefficients: c_1 = 2 c_2 = 2 c_3 = 1 c_4 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 HCl + 2 Rb ⟶ H_2 + 2 RbCl