Na2SO4 + FeCl3 = NaCl + Fe2(SO4)3

Na_2SO_4 sodium sulfate + FeCl_3 iron(III) chloride ⟶ NaCl sodium chloride + Fe_2(SO_4)_3·xH_2O iron(III) sulfate hydrate

Balance the chemical equation algebraically: Na_2SO_4 + FeCl_3 ⟶ NaCl + Fe_2(SO_4)_3·xH_2O Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Na_2SO_4 + c_2 FeCl_3 ⟶ c_3 NaCl + c_4 Fe_2(SO_4)_3·xH_2O Set the number of atoms in the reactants equal to the number of atoms in the products for Na, O, S, Cl and Fe: Na: | 2 c_1 = c_3 O: | 4 c_1 = 12 c_4 S: | c_1 = 3 c_4 Cl: | 3 c_2 = c_3 Fe: | c_2 = 2 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 = 3 c_2 = 2 c_3 = 6 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 3 Na_2SO_4 + 2 FeCl_3 ⟶ 6 NaCl + Fe_2(SO_4)_3·xH_2O

+ ⟶ +

sodium sulfate + iron(III) chloride ⟶ sodium chloride + iron(III) sulfate hydrate

Construct the equilibrium constant, K, expression for: Na_2SO_4 + FeCl_3 ⟶ NaCl + Fe_2(SO_4)_3·xH_2O 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: 3 Na_2SO_4 + 2 FeCl_3 ⟶ 6 NaCl + Fe_2(SO_4)_3·xH_2O 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 Na_2SO_4 | 3 | -3 FeCl_3 | 2 | -2 NaCl | 6 | 6 Fe_2(SO_4)_3·xH_2O | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Na_2SO_4 | 3 | -3 | ([Na2SO4])^(-3) FeCl_3 | 2 | -2 | ([FeCl3])^(-2) NaCl | 6 | 6 | ([NaCl])^6 Fe_2(SO_4)_3·xH_2O | 1 | 1 | [Fe2(SO4)3·xH2O] 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 = ([Na2SO4])^(-3) ([FeCl3])^(-2) ([NaCl])^6 [Fe2(SO4)3·xH2O] = (([NaCl])^6 [Fe2(SO4)3·xH2O])/(([Na2SO4])^3 ([FeCl3])^2)

Construct the rate of reaction expression for: Na_2SO_4 + FeCl_3 ⟶ NaCl + Fe_2(SO_4)_3·xH_2O 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: 3 Na_2SO_4 + 2 FeCl_3 ⟶ 6 NaCl + Fe_2(SO_4)_3·xH_2O 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 Na_2SO_4 | 3 | -3 FeCl_3 | 2 | -2 NaCl | 6 | 6 Fe_2(SO_4)_3·xH_2O | 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 Na_2SO_4 | 3 | -3 | -1/3 (Δ[Na2SO4])/(Δt) FeCl_3 | 2 | -2 | -1/2 (Δ[FeCl3])/(Δt) NaCl | 6 | 6 | 1/6 (Δ[NaCl])/(Δt) Fe_2(SO_4)_3·xH_2O | 1 | 1 | (Δ[Fe2(SO4)3·xH2O])/(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 = -1/3 (Δ[Na2SO4])/(Δt) = -1/2 (Δ[FeCl3])/(Δt) = 1/6 (Δ[NaCl])/(Δt) = (Δ[Fe2(SO4)3·xH2O])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| sodium sulfate | iron(III) chloride | sodium chloride | iron(III) sulfate hydrate formula | Na_2SO_4 | FeCl_3 | NaCl | Fe_2(SO_4)_3·xH_2O Hill formula | Na_2O_4S | Cl_3Fe | ClNa | Fe_2O_12S_3 name | sodium sulfate | iron(III) chloride | sodium chloride | iron(III) sulfate hydrate IUPAC name | disodium sulfate | trichloroiron | sodium chloride | diferric trisulfate

| sodium sulfate | iron(III) chloride | sodium chloride | iron(III) sulfate hydrate molar mass | 142.04 g/mol | 162.2 g/mol | 58.44 g/mol | 399.9 g/mol phase | solid (at STP) | solid (at STP) | solid (at STP) | melting point | 884 °C | 304 °C | 801 °C | boiling point | 1429 °C | | 1413 °C | density | 2.68 g/cm^3 | | 2.16 g/cm^3 | solubility in water | soluble | | soluble | slightly soluble odor | | | odorless |