FeCl3 + Na2O = NaCl + Fe2O3

FeCl_3 iron(III) chloride + Na_2O sodium oxide ⟶ NaCl sodium chloride + Fe_2O_3 iron(III) oxide

Balance the chemical equation algebraically: FeCl_3 + Na_2O ⟶ NaCl + Fe_2O_3 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 FeCl_3 + c_2 Na_2O ⟶ c_3 NaCl + c_4 Fe_2O_3 Set the number of atoms in the reactants equal to the number of atoms in the products for Cl, Fe, Na and O: Cl: | 3 c_1 = c_3 Fe: | c_1 = 2 c_4 Na: | 2 c_2 = c_3 O: | c_2 = 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_4 = 1 and solve the system of equations for the remaining coefficients: c_1 = 2 c_2 = 3 c_3 = 6 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 FeCl_3 + 3 Na_2O ⟶ 6 NaCl + Fe_2O_3

+ ⟶ +

iron(III) chloride + sodium oxide ⟶ sodium chloride + iron(III) oxide

Construct the equilibrium constant, K, expression for: FeCl_3 + Na_2O ⟶ NaCl + Fe_2O_3 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 FeCl_3 + 3 Na_2O ⟶ 6 NaCl + Fe_2O_3 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 FeCl_3 | 2 | -2 Na_2O | 3 | -3 NaCl | 6 | 6 Fe_2O_3 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression FeCl_3 | 2 | -2 | ([FeCl3])^(-2) Na_2O | 3 | -3 | ([Na2O])^(-3) NaCl | 6 | 6 | ([NaCl])^6 Fe_2O_3 | 1 | 1 | [Fe2O3] 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 = ([FeCl3])^(-2) ([Na2O])^(-3) ([NaCl])^6 [Fe2O3] = (([NaCl])^6 [Fe2O3])/(([FeCl3])^2 ([Na2O])^3)

Construct the rate of reaction expression for: FeCl_3 + Na_2O ⟶ NaCl + Fe_2O_3 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 FeCl_3 + 3 Na_2O ⟶ 6 NaCl + Fe_2O_3 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 FeCl_3 | 2 | -2 Na_2O | 3 | -3 NaCl | 6 | 6 Fe_2O_3 | 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 FeCl_3 | 2 | -2 | -1/2 (Δ[FeCl3])/(Δt) Na_2O | 3 | -3 | -1/3 (Δ[Na2O])/(Δt) NaCl | 6 | 6 | 1/6 (Δ[NaCl])/(Δt) Fe_2O_3 | 1 | 1 | (Δ[Fe2O3])/(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[FeCl3])/(Δt) = -1/3 (Δ[Na2O])/(Δt) = 1/6 (Δ[NaCl])/(Δt) = (Δ[Fe2O3])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| iron(III) chloride | sodium oxide | sodium chloride | iron(III) oxide formula | FeCl_3 | Na_2O | NaCl | Fe_2O_3 Hill formula | Cl_3Fe | Na_2O | ClNa | Fe_2O_3 name | iron(III) chloride | sodium oxide | sodium chloride | iron(III) oxide IUPAC name | trichloroiron | disodium oxygen(-2) anion | sodium chloride |

| iron(III) chloride | sodium oxide | sodium chloride | iron(III) oxide molar mass | 162.2 g/mol | 61.979 g/mol | 58.44 g/mol | 159.69 g/mol phase | solid (at STP) | | solid (at STP) | solid (at STP) melting point | 304 °C | | 801 °C | 1565 °C boiling point | | | 1413 °C | density | | 2.27 g/cm^3 | 2.16 g/cm^3 | 5.26 g/cm^3 solubility in water | | | soluble | insoluble odor | | | odorless | odorless