HCl + KI + CaOCl2 = H2O + I2 + KCl + CaCl2

HCl hydrogen chloride + KI potassium iodide + CaOCl2 ⟶ H_2O water + I_2 iodine + KCl potassium chloride + CaCl_2 calcium chloride

Balance the chemical equation algebraically: HCl + KI + CaOCl2 ⟶ H_2O + I_2 + KCl + CaCl_2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 HCl + c_2 KI + c_3 CaOCl2 ⟶ c_4 H_2O + c_5 I_2 + c_6 KCl + c_7 CaCl_2 Set the number of atoms in the reactants equal to the number of atoms in the products for Cl, H, I, K, Ca and O: Cl: | c_1 + 2 c_3 = c_6 + 2 c_7 H: | c_1 = 2 c_4 I: | c_2 = 2 c_5 K: | c_2 = c_6 Ca: | c_3 = c_7 O: | c_3 = 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 = 1 c_5 = 1 c_6 = 2 c_7 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 HCl + 2 KI + CaOCl2 ⟶ H_2O + I_2 + 2 KCl + CaCl_2

+ + CaOCl2 ⟶ + + +

hydrogen chloride + potassium iodide + CaOCl2 ⟶ water + iodine + potassium chloride + calcium chloride

Construct the equilibrium constant, K, expression for: HCl + KI + CaOCl2 ⟶ H_2O + I_2 + KCl + CaCl_2 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 HCl + 2 KI + CaOCl2 ⟶ H_2O + I_2 + 2 KCl + CaCl_2 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 | 2 | -2 KI | 2 | -2 CaOCl2 | 1 | -1 H_2O | 1 | 1 I_2 | 1 | 1 KCl | 2 | 2 CaCl_2 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression HCl | 2 | -2 | ([HCl])^(-2) KI | 2 | -2 | ([KI])^(-2) CaOCl2 | 1 | -1 | ([CaOCl2])^(-1) H_2O | 1 | 1 | [H2O] I_2 | 1 | 1 | [I2] KCl | 2 | 2 | ([KCl])^2 CaCl_2 | 1 | 1 | [CaCl2] 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])^(-2) ([KI])^(-2) ([CaOCl2])^(-1) [H2O] [I2] ([KCl])^2 [CaCl2] = ([H2O] [I2] ([KCl])^2 [CaCl2])/(([HCl])^2 ([KI])^2 [CaOCl2])

Construct the rate of reaction expression for: HCl + KI + CaOCl2 ⟶ H_2O + I_2 + KCl + CaCl_2 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 HCl + 2 KI + CaOCl2 ⟶ H_2O + I_2 + 2 KCl + CaCl_2 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 | 2 | -2 KI | 2 | -2 CaOCl2 | 1 | -1 H_2O | 1 | 1 I_2 | 1 | 1 KCl | 2 | 2 CaCl_2 | 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 | 2 | -2 | -1/2 (Δ[HCl])/(Δt) KI | 2 | -2 | -1/2 (Δ[KI])/(Δt) CaOCl2 | 1 | -1 | -(Δ[CaOCl2])/(Δt) H_2O | 1 | 1 | (Δ[H2O])/(Δt) I_2 | 1 | 1 | (Δ[I2])/(Δt) KCl | 2 | 2 | 1/2 (Δ[KCl])/(Δt) CaCl_2 | 1 | 1 | (Δ[CaCl2])/(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[HCl])/(Δt) = -1/2 (Δ[KI])/(Δt) = -(Δ[CaOCl2])/(Δt) = (Δ[H2O])/(Δt) = (Δ[I2])/(Δt) = 1/2 (Δ[KCl])/(Δt) = (Δ[CaCl2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| hydrogen chloride | potassium iodide | CaOCl2 | water | iodine | potassium chloride | calcium chloride formula | HCl | KI | CaOCl2 | H_2O | I_2 | KCl | CaCl_2 Hill formula | ClH | IK | CaCl2O | H_2O | I_2 | ClK | CaCl_2 name | hydrogen chloride | potassium iodide | | water | iodine | potassium chloride | calcium chloride IUPAC name | hydrogen chloride | potassium iodide | | water | molecular iodine | potassium chloride | calcium dichloride

| hydrogen chloride | potassium iodide | CaOCl2 | water | iodine | potassium chloride | calcium chloride molar mass | 36.46 g/mol | 166.0028 g/mol | 127 g/mol | 18.015 g/mol | 253.80894 g/mol | 74.55 g/mol | 111 g/mol phase | gas (at STP) | solid (at STP) | | liquid (at STP) | solid (at STP) | solid (at STP) | solid (at STP) melting point | -114.17 °C | 681 °C | | 0 °C | 113 °C | 770 °C | 772 °C boiling point | -85 °C | 1330 °C | | 99.9839 °C | 184 °C | 1420 °C | density | 0.00149 g/cm^3 (at 25 °C) | 3.123 g/cm^3 | | 1 g/cm^3 | 4.94 g/cm^3 | 1.98 g/cm^3 | 2.15 g/cm^3 solubility in water | miscible | | | | | soluble | soluble surface tension | | | | 0.0728 N/m | | | dynamic viscosity | | 0.0010227 Pa s (at 732.9 °C) | | 8.9×10^-4 Pa s (at 25 °C) | 0.00227 Pa s (at 116 °C) | | odor | | | | odorless | | odorless |