Al + CuCl2 = Cu + AlCl2

Al aluminum + CuCl_2 copper(II) chloride ⟶ Cu copper + AlCl2

Balance the chemical equation algebraically: Al + CuCl_2 ⟶ Cu + AlCl2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Al + c_2 CuCl_2 ⟶ c_3 Cu + c_4 AlCl2 Set the number of atoms in the reactants equal to the number of atoms in the products for Al, Cl and Cu: Al: | c_1 = c_4 Cl: | 2 c_2 = 2 c_4 Cu: | 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_1 = 1 and solve the system of equations for the remaining coefficients: c_1 = 1 c_2 = 1 c_3 = 1 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | Al + CuCl_2 ⟶ Cu + AlCl2

+ ⟶ + AlCl2

aluminum + copper(II) chloride ⟶ copper + AlCl2

Construct the equilibrium constant, K, expression for: Al + CuCl_2 ⟶ Cu + AlCl2 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: Al + CuCl_2 ⟶ Cu + AlCl2 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 Al | 1 | -1 CuCl_2 | 1 | -1 Cu | 1 | 1 AlCl2 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Al | 1 | -1 | ([Al])^(-1) CuCl_2 | 1 | -1 | ([CuCl2])^(-1) Cu | 1 | 1 | [Cu] AlCl2 | 1 | 1 | [AlCl2] 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 = ([Al])^(-1) ([CuCl2])^(-1) [Cu] [AlCl2] = ([Cu] [AlCl2])/([Al] [CuCl2])

Construct the rate of reaction expression for: Al + CuCl_2 ⟶ Cu + AlCl2 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: Al + CuCl_2 ⟶ Cu + AlCl2 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 Al | 1 | -1 CuCl_2 | 1 | -1 Cu | 1 | 1 AlCl2 | 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 Al | 1 | -1 | -(Δ[Al])/(Δt) CuCl_2 | 1 | -1 | -(Δ[CuCl2])/(Δt) Cu | 1 | 1 | (Δ[Cu])/(Δt) AlCl2 | 1 | 1 | (Δ[AlCl2])/(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[Al])/(Δt) = -(Δ[CuCl2])/(Δt) = (Δ[Cu])/(Δt) = (Δ[AlCl2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| aluminum | copper(II) chloride | copper | AlCl2 formula | Al | CuCl_2 | Cu | AlCl2 Hill formula | Al | Cl_2Cu | Cu | AlCl2 name | aluminum | copper(II) chloride | copper | IUPAC name | aluminum | dichlorocopper | copper |

| aluminum | copper(II) chloride | copper | AlCl2 molar mass | 26.9815385 g/mol | 134.4 g/mol | 63.546 g/mol | 97.88 g/mol phase | solid (at STP) | solid (at STP) | solid (at STP) | melting point | 660.4 °C | 620 °C | 1083 °C | boiling point | 2460 °C | | 2567 °C | density | 2.7 g/cm^3 | 3.386 g/cm^3 | 8.96 g/cm^3 | solubility in water | insoluble | | insoluble | surface tension | 0.817 N/m | | | dynamic viscosity | 1.5×10^-4 Pa s (at 760 °C) | | | odor | odorless | | odorless |