CuI2 = I2 + Cu

CuI2 ⟶ I_2 iodine + Cu copper

Balance the chemical equation algebraically: CuI2 ⟶ I_2 + Cu Add stoichiometric coefficients, c_i, to the reactants and products: c_1 CuI2 ⟶ c_2 I_2 + c_3 Cu Set the number of atoms in the reactants equal to the number of atoms in the products for Cu and I: Cu: | c_1 = c_3 I: | 2 c_1 = 2 c_2 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_1 = 1 and solve the system of equations for the remaining coefficients: c_1 = 1 c_2 = 1 c_3 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | CuI2 ⟶ I_2 + Cu

CuI2 ⟶ +

CuI2 ⟶ iodine + copper

Construct the equilibrium constant, K, expression for: CuI2 ⟶ I_2 + Cu 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: CuI2 ⟶ I_2 + Cu 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 CuI2 | 1 | -1 I_2 | 1 | 1 Cu | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression CuI2 | 1 | -1 | ([CuI2])^(-1) I_2 | 1 | 1 | [I2] Cu | 1 | 1 | [Cu] 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 = ([CuI2])^(-1) [I2] [Cu] = ([I2] [Cu])/([CuI2])

Construct the rate of reaction expression for: CuI2 ⟶ I_2 + Cu 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: CuI2 ⟶ I_2 + Cu 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 CuI2 | 1 | -1 I_2 | 1 | 1 Cu | 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 CuI2 | 1 | -1 | -(Δ[CuI2])/(Δt) I_2 | 1 | 1 | (Δ[I2])/(Δt) Cu | 1 | 1 | (Δ[Cu])/(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 = -(Δ[CuI2])/(Δt) = (Δ[I2])/(Δt) = (Δ[Cu])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| CuI2 | iodine | copper formula | CuI2 | I_2 | Cu name | | iodine | copper IUPAC name | | molecular iodine | copper

| CuI2 | iodine | copper molar mass | 317.355 g/mol | 253.80894 g/mol | 63.546 g/mol phase | | solid (at STP) | solid (at STP) melting point | | 113 °C | 1083 °C boiling point | | 184 °C | 2567 °C density | | 4.94 g/cm^3 | 8.96 g/cm^3 solubility in water | | | insoluble dynamic viscosity | | 0.00227 Pa s (at 116 °C) | odor | | | odorless