H2O + NaCl = Cl2 + H2 + NaOH

water + sodium chloride ⟶ chlorine + hydrogen + sodium hydroxide

Balance the chemical equation algebraically: + ⟶ + + Add stoichiometric coefficients, c_i, to the reactants and products: c_1 + c_2 ⟶ c_3 + c_4 + c_5 Set the number of atoms in the reactants equal to the number of atoms in the products for H, O, Cl and Na: H: | 2 c_1 = 2 c_4 + c_5 O: | c_1 = c_5 Cl: | c_2 = 2 c_3 Na: | c_2 = c_5 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 = 1 c_5 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 + 2 ⟶ + + 2

+ ⟶ + +

water + sodium chloride ⟶ chlorine + hydrogen + sodium hydroxide

| water | sodium chloride | chlorine | hydrogen | sodium hydroxide molecular enthalpy | -285.8 kJ/mol | -411.2 kJ/mol | 0 kJ/mol | 0 kJ/mol | -425.8 kJ/mol total enthalpy | -571.7 kJ/mol | -822.4 kJ/mol | 0 kJ/mol | 0 kJ/mol | -851.6 kJ/mol | H_initial = -1394 kJ/mol | | H_final = -851.6 kJ/mol | | ΔH_rxn^0 | -851.6 kJ/mol - -1394 kJ/mol = 542.5 kJ/mol (endothermic) | | | |

| water | sodium chloride | chlorine | hydrogen | sodium hydroxide molecular free energy | -237.1 kJ/mol | -384.1 kJ/mol | 0 kJ/mol | 0 kJ/mol | -379.7 kJ/mol total free energy | -474.2 kJ/mol | -768.2 kJ/mol | 0 kJ/mol | 0 kJ/mol | -759.4 kJ/mol | G_initial = -1242 kJ/mol | | G_final = -759.4 kJ/mol | | ΔG_rxn^0 | -759.4 kJ/mol - -1242 kJ/mol = 483 kJ/mol (endergonic) | | | |

| water | sodium chloride | chlorine | hydrogen | sodium hydroxide molecular entropy | 69.91 J/(mol K) | 72 J/(mol K) | 223 J/(mol K) | 115 J/(mol K) | 64 J/(mol K) total entropy | 139.8 J/(mol K) | 144 J/(mol K) | 223 J/(mol K) | 115 J/(mol K) | 128 J/(mol K) | S_initial = 283.8 J/(mol K) | | S_final = 466 J/(mol K) | | ΔS_rxn^0 | 466 J/(mol K) - 283.8 J/(mol K) = 182.2 J/(mol K) (endoentropic) | | | |

| water | sodium chloride | chlorine | hydrogen | sodium hydroxide Hill formula | H_2O | ClNa | Cl_2 | H_2 | HNaO name | water | sodium chloride | chlorine | hydrogen | sodium hydroxide IUPAC name | water | sodium chloride | molecular chlorine | molecular hydrogen | sodium hydroxide