HCl + KMnO4 = H2O + Cl2 + KCl + MnCl

HCl hydrogen chloride + KMnO_4 potassium permanganate ⟶ H_2O water + Cl_2 chlorine + KCl potassium chloride + MnCl

Balance the chemical equation algebraically: HCl + KMnO_4 ⟶ H_2O + Cl_2 + KCl + MnCl Add stoichiometric coefficients, c_i, to the reactants and products: c_1 HCl + c_2 KMnO_4 ⟶ c_3 H_2O + c_4 Cl_2 + c_5 KCl + c_6 MnCl Set the number of atoms in the reactants equal to the number of atoms in the products for Cl, H, K, Mn and O: Cl: | c_1 = 2 c_4 + c_5 + c_6 H: | c_1 = 2 c_3 K: | c_2 = c_5 Mn: | c_2 = c_6 O: | 4 c_2 = c_3 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 = 8 c_2 = 1 c_3 = 4 c_4 = 3 c_5 = 1 c_6 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 8 HCl + KMnO_4 ⟶ 4 H_2O + 3 Cl_2 + KCl + MnCl

+ ⟶ + + + MnCl

hydrogen chloride + potassium permanganate ⟶ water + chlorine + potassium chloride + MnCl

Construct the equilibrium constant, K, expression for: HCl + KMnO_4 ⟶ H_2O + Cl_2 + KCl + MnCl Plan: • Balance the chemical equation. • Determine the stoichiometric numbers. • Assemble the activity expression for each chemical species. • Use the activity expressions to build the equilibrium constant expression. Write the balanced chemical equation: 8 HCl + KMnO_4 ⟶ 4 H_2O + 3 Cl_2 + KCl + MnCl Assign stoichiometric numbers, ν_i, using the stoichiometric coefficients, c_i, from the balanced chemical equation in the following manner: ν_i = -c_i for reactants and ν_i = c_i for products: chemical species | c_i | ν_i HCl | 8 | -8 KMnO_4 | 1 | -1 H_2O | 4 | 4 Cl_2 | 3 | 3 KCl | 1 | 1 MnCl | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression HCl | 8 | -8 | ([HCl])^(-8) KMnO_4 | 1 | -1 | ([KMnO4])^(-1) H_2O | 4 | 4 | ([H2O])^4 Cl_2 | 3 | 3 | ([Cl2])^3 KCl | 1 | 1 | [KCl] MnCl | 1 | 1 | [MnCl] The equilibrium constant symbol in the concentration basis is: K_c Mulitply the activity expressions to arrive at the K_c expression: Answer: | | K_c = ([HCl])^(-8) ([KMnO4])^(-1) ([H2O])^4 ([Cl2])^3 [KCl] [MnCl] = (([H2O])^4 ([Cl2])^3 [KCl] [MnCl])/(([HCl])^8 [KMnO4])

Construct the rate of reaction expression for: HCl + KMnO_4 ⟶ H_2O + Cl_2 + KCl + MnCl Plan: • Balance the chemical equation. • Determine the stoichiometric numbers. • Assemble the rate term for each chemical species. • Write the rate of reaction expression. Write the balanced chemical equation: 8 HCl + KMnO_4 ⟶ 4 H_2O + 3 Cl_2 + KCl + MnCl Assign stoichiometric numbers, ν_i, using the stoichiometric coefficients, c_i, from the balanced chemical equation in the following manner: ν_i = -c_i for reactants and ν_i = c_i for products: chemical species | c_i | ν_i HCl | 8 | -8 KMnO_4 | 1 | -1 H_2O | 4 | 4 Cl_2 | 3 | 3 KCl | 1 | 1 MnCl | 1 | 1 The rate term for each chemical species, B_i, is 1/ν_i(Δ[B_i])/(Δt) where [B_i] is the amount concentration and t is time: chemical species | c_i | ν_i | rate term HCl | 8 | -8 | -1/8 (Δ[HCl])/(Δt) KMnO_4 | 1 | -1 | -(Δ[KMnO4])/(Δt) H_2O | 4 | 4 | 1/4 (Δ[H2O])/(Δt) Cl_2 | 3 | 3 | 1/3 (Δ[Cl2])/(Δt) KCl | 1 | 1 | (Δ[KCl])/(Δt) MnCl | 1 | 1 | (Δ[MnCl])/(Δt) (for infinitesimal rate of change, replace Δ with d) Set the rate terms equal to each other to arrive at the rate expression: Answer: | | rate = -1/8 (Δ[HCl])/(Δt) = -(Δ[KMnO4])/(Δt) = 1/4 (Δ[H2O])/(Δt) = 1/3 (Δ[Cl2])/(Δt) = (Δ[KCl])/(Δt) = (Δ[MnCl])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| hydrogen chloride | potassium permanganate | water | chlorine | potassium chloride | MnCl formula | HCl | KMnO_4 | H_2O | Cl_2 | KCl | MnCl Hill formula | ClH | KMnO_4 | H_2O | Cl_2 | ClK | ClMn name | hydrogen chloride | potassium permanganate | water | chlorine | potassium chloride | IUPAC name | hydrogen chloride | potassium permanganate | water | molecular chlorine | potassium chloride |

| hydrogen chloride | potassium permanganate | water | chlorine | potassium chloride | MnCl molar mass | 36.46 g/mol | 158.03 g/mol | 18.015 g/mol | 70.9 g/mol | 74.55 g/mol | 90.39 g/mol phase | gas (at STP) | solid (at STP) | liquid (at STP) | gas (at STP) | solid (at STP) | melting point | -114.17 °C | 240 °C | 0 °C | -101 °C | 770 °C | boiling point | -85 °C | | 99.9839 °C | -34 °C | 1420 °C | density | 0.00149 g/cm^3 (at 25 °C) | 1 g/cm^3 | 1 g/cm^3 | 0.003214 g/cm^3 (at 0 °C) | 1.98 g/cm^3 | solubility in water | miscible | | | | soluble | surface tension | | | 0.0728 N/m | | | dynamic viscosity | | | 8.9×10^-4 Pa s (at 25 °C) | | | odor | | odorless | odorless | | odorless |