H2O + KMnO4 + KI = KOH + I2 + MnO2

water + potassium permanganate + potassium iodide ⟶ potassium hydroxide + iodine + manganese dioxide

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 + c_6 Set the number of atoms in the reactants equal to the number of atoms in the products for H, O, K, Mn and I: H: | 2 c_1 = c_4 O: | c_1 + 4 c_2 = c_4 + 2 c_6 K: | c_2 + c_3 = c_4 Mn: | c_2 = c_6 I: | c_3 = 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_2 = 1 and solve the system of equations for the remaining coefficients: c_1 = 2 c_2 = 1 c_3 = 3 c_4 = 4 c_5 = 3/2 c_6 = 1 Multiply by the least common denominator, 2, to eliminate fractional coefficients: c_1 = 4 c_2 = 2 c_3 = 6 c_4 = 8 c_5 = 3 c_6 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 4 + 2 + 6 ⟶ 8 + 3 + 2

+ + ⟶ + +

water + potassium permanganate + potassium iodide ⟶ potassium hydroxide + iodine + manganese dioxide

| water | potassium permanganate | potassium iodide | potassium hydroxide | iodine | manganese dioxide molecular free energy | -237.1 kJ/mol | -737.6 kJ/mol | -324.9 kJ/mol | -379.4 kJ/mol | 0 kJ/mol | -465.1 kJ/mol total free energy | -948.4 kJ/mol | -1475 kJ/mol | -1949 kJ/mol | -3035 kJ/mol | 0 kJ/mol | -930.2 kJ/mol | G_initial = -4373 kJ/mol | | | G_final = -3965 kJ/mol | | ΔG_rxn^0 | -3965 kJ/mol - -4373 kJ/mol = 407.6 kJ/mol (endergonic) | | | | |

K_c = ([KOH]^8 [I2]^3 [MnO2]^2)/([H2O]^4 [KMnO4]^2 [KI]^6)

rate = -1/4 (Δ[H2O])/(Δt) = -1/2 (Δ[KMnO4])/(Δt) = -1/6 (Δ[KI])/(Δt) = 1/8 (Δ[KOH])/(Δt) = 1/3 (Δ[I2])/(Δt) = 1/2 (Δ[MnO2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| water | potassium permanganate | potassium iodide | potassium hydroxide | iodine | manganese dioxide Hill formula | H_2O | KMnO_4 | IK | HKO | I_2 | MnO_2 name | water | potassium permanganate | potassium iodide | potassium hydroxide | iodine | manganese dioxide IUPAC name | water | potassium permanganate | potassium iodide | potassium hydroxide | molecular iodine | dioxomanganese