CuCl = Cu + CuCl2

CuCl cuprous chloride ⟶ Cu copper + CuCl_2 copper(II) chloride

Balance the chemical equation algebraically: CuCl ⟶ Cu + CuCl_2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 CuCl ⟶ c_2 Cu + c_3 CuCl_2 Set the number of atoms in the reactants equal to the number of atoms in the products for Cl and Cu: Cl: | c_1 = 2 c_3 Cu: | c_1 = 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 = 2 c_2 = 1 c_3 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 CuCl ⟶ Cu + CuCl_2

⟶ +

cuprous chloride ⟶ copper + copper(II) chloride

| cuprous chloride | copper | copper(II) chloride molecular enthalpy | -137.2 kJ/mol | 0 kJ/mol | -220.1 kJ/mol total enthalpy | -274.4 kJ/mol | 0 kJ/mol | -220.1 kJ/mol | H_initial = -274.4 kJ/mol | H_final = -220.1 kJ/mol | ΔH_rxn^0 | -220.1 kJ/mol - -274.4 kJ/mol = 54.3 kJ/mol (endothermic) | |

Construct the equilibrium constant, K, expression for: CuCl ⟶ Cu + CuCl_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 CuCl ⟶ Cu + CuCl_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 CuCl | 2 | -2 Cu | 1 | 1 CuCl_2 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression CuCl | 2 | -2 | ([CuCl])^(-2) Cu | 1 | 1 | [Cu] CuCl_2 | 1 | 1 | [CuCl2] 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 = ([CuCl])^(-2) [Cu] [CuCl2] = ([Cu] [CuCl2])/([CuCl])^2

Construct the rate of reaction expression for: CuCl ⟶ Cu + CuCl_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 CuCl ⟶ Cu + CuCl_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 CuCl | 2 | -2 Cu | 1 | 1 CuCl_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 CuCl | 2 | -2 | -1/2 (Δ[CuCl])/(Δt) Cu | 1 | 1 | (Δ[Cu])/(Δt) CuCl_2 | 1 | 1 | (Δ[CuCl2])/(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[CuCl])/(Δt) = (Δ[Cu])/(Δt) = (Δ[CuCl2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| cuprous chloride | copper | copper(II) chloride formula | CuCl | Cu | CuCl_2 Hill formula | ClCu | Cu | Cl_2Cu name | cuprous chloride | copper | copper(II) chloride IUPAC name | | copper | dichlorocopper

| cuprous chloride | copper | copper(II) chloride molar mass | 99 g/mol | 63.546 g/mol | 134.4 g/mol phase | solid (at STP) | solid (at STP) | solid (at STP) melting point | 430 °C | 1083 °C | 620 °C boiling point | 1490 °C | 2567 °C | density | 4.145 g/cm^3 | 8.96 g/cm^3 | 3.386 g/cm^3 solubility in water | | insoluble | odor | | odorless |