Cu + FeCl3 = FeCl2 + CuCl

Cu copper + FeCl_3 iron(III) chloride ⟶ FeCl_2 iron(II) chloride + CuCl cuprous chloride

Balance the chemical equation algebraically: Cu + FeCl_3 ⟶ FeCl_2 + CuCl Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Cu + c_2 FeCl_3 ⟶ c_3 FeCl_2 + c_4 CuCl Set the number of atoms in the reactants equal to the number of atoms in the products for Cu, Cl and Fe: Cu: | c_1 = c_4 Cl: | 3 c_2 = 2 c_3 + c_4 Fe: | 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: | | Cu + FeCl_3 ⟶ FeCl_2 + CuCl

+ ⟶ +

copper + iron(III) chloride ⟶ iron(II) chloride + cuprous chloride

| copper | iron(III) chloride | iron(II) chloride | cuprous chloride molecular enthalpy | 0 kJ/mol | -399.5 kJ/mol | -341.8 kJ/mol | -137.2 kJ/mol total enthalpy | 0 kJ/mol | -399.5 kJ/mol | -341.8 kJ/mol | -137.2 kJ/mol | H_initial = -399.5 kJ/mol | | H_final = -479 kJ/mol | ΔH_rxn^0 | -479 kJ/mol - -399.5 kJ/mol = -79.5 kJ/mol (exothermic) | | |

Construct the equilibrium constant, K, expression for: Cu + FeCl_3 ⟶ FeCl_2 + CuCl 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: Cu + FeCl_3 ⟶ FeCl_2 + CuCl 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 Cu | 1 | -1 FeCl_3 | 1 | -1 FeCl_2 | 1 | 1 CuCl | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Cu | 1 | -1 | ([Cu])^(-1) FeCl_3 | 1 | -1 | ([FeCl3])^(-1) FeCl_2 | 1 | 1 | [FeCl2] CuCl | 1 | 1 | [CuCl] 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 = ([Cu])^(-1) ([FeCl3])^(-1) [FeCl2] [CuCl] = ([FeCl2] [CuCl])/([Cu] [FeCl3])

Construct the rate of reaction expression for: Cu + FeCl_3 ⟶ FeCl_2 + CuCl 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: Cu + FeCl_3 ⟶ FeCl_2 + CuCl 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 Cu | 1 | -1 FeCl_3 | 1 | -1 FeCl_2 | 1 | 1 CuCl | 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 Cu | 1 | -1 | -(Δ[Cu])/(Δt) FeCl_3 | 1 | -1 | -(Δ[FeCl3])/(Δt) FeCl_2 | 1 | 1 | (Δ[FeCl2])/(Δt) CuCl | 1 | 1 | (Δ[CuCl])/(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[Cu])/(Δt) = -(Δ[FeCl3])/(Δt) = (Δ[FeCl2])/(Δt) = (Δ[CuCl])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| copper | iron(III) chloride | iron(II) chloride | cuprous chloride formula | Cu | FeCl_3 | FeCl_2 | CuCl Hill formula | Cu | Cl_3Fe | Cl_2Fe | ClCu name | copper | iron(III) chloride | iron(II) chloride | cuprous chloride IUPAC name | copper | trichloroiron | dichloroiron |

| copper | iron(III) chloride | iron(II) chloride | cuprous chloride molar mass | 63.546 g/mol | 162.2 g/mol | 126.7 g/mol | 99 g/mol phase | solid (at STP) | solid (at STP) | solid (at STP) | solid (at STP) melting point | 1083 °C | 304 °C | 677 °C | 430 °C boiling point | 2567 °C | | | 1490 °C density | 8.96 g/cm^3 | | 3.16 g/cm^3 | 4.145 g/cm^3 solubility in water | insoluble | | | odor | odorless | | |