H2O + Cl2 + I2 = HCl + HIO

H_2O water + Cl_2 chlorine + I_2 iodine ⟶ HCl hydrogen chloride + HOI hypoiodous acid

Balance the chemical equation algebraically: H_2O + Cl_2 + I_2 ⟶ HCl + HOI Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_2O + c_2 Cl_2 + c_3 I_2 ⟶ c_4 HCl + c_5 HOI Set the number of atoms in the reactants equal to the number of atoms in the products for H, O, Cl and I: H: | 2 c_1 = c_4 + c_5 O: | c_1 = c_5 Cl: | 2 c_2 = c_4 I: | 2 c_3 = 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 = 1 c_4 = 2 c_5 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 H_2O + Cl_2 + I_2 ⟶ 2 HCl + 2 HOI

+ + ⟶ +

water + chlorine + iodine ⟶ hydrogen chloride + hypoiodous acid

Construct the equilibrium constant, K, expression for: H_2O + Cl_2 + I_2 ⟶ HCl + HOI 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: 2 H_2O + Cl_2 + I_2 ⟶ 2 HCl + 2 HOI 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 H_2O | 2 | -2 Cl_2 | 1 | -1 I_2 | 1 | -1 HCl | 2 | 2 HOI | 2 | 2 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression H_2O | 2 | -2 | ([H2O])^(-2) Cl_2 | 1 | -1 | ([Cl2])^(-1) I_2 | 1 | -1 | ([I2])^(-1) HCl | 2 | 2 | ([HCl])^2 HOI | 2 | 2 | ([HOI])^2 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 = ([H2O])^(-2) ([Cl2])^(-1) ([I2])^(-1) ([HCl])^2 ([HOI])^2 = (([HCl])^2 ([HOI])^2)/(([H2O])^2 [Cl2] [I2])

Construct the rate of reaction expression for: H_2O + Cl_2 + I_2 ⟶ HCl + HOI 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: 2 H_2O + Cl_2 + I_2 ⟶ 2 HCl + 2 HOI 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 H_2O | 2 | -2 Cl_2 | 1 | -1 I_2 | 1 | -1 HCl | 2 | 2 HOI | 2 | 2 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 H_2O | 2 | -2 | -1/2 (Δ[H2O])/(Δt) Cl_2 | 1 | -1 | -(Δ[Cl2])/(Δt) I_2 | 1 | -1 | -(Δ[I2])/(Δt) HCl | 2 | 2 | 1/2 (Δ[HCl])/(Δt) HOI | 2 | 2 | 1/2 (Δ[HOI])/(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 = -1/2 (Δ[H2O])/(Δt) = -(Δ[Cl2])/(Δt) = -(Δ[I2])/(Δt) = 1/2 (Δ[HCl])/(Δt) = 1/2 (Δ[HOI])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| water | chlorine | iodine | hydrogen chloride | hypoiodous acid formula | H_2O | Cl_2 | I_2 | HCl | HOI Hill formula | H_2O | Cl_2 | I_2 | ClH | HIO name | water | chlorine | iodine | hydrogen chloride | hypoiodous acid IUPAC name | water | molecular chlorine | molecular iodine | hydrogen chloride | hypoiodous acid