Fe + SnCl4 = FeCl3 + SnCl2

Fe iron + SnCl_4 stannic chloride ⟶ FeCl_3 iron(III) chloride + SnCl_2 stannous chloride

Balance the chemical equation algebraically: Fe + SnCl_4 ⟶ FeCl_3 + SnCl_2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Fe + c_2 SnCl_4 ⟶ c_3 FeCl_3 + c_4 SnCl_2 Set the number of atoms in the reactants equal to the number of atoms in the products for Fe, Cl and Sn: Fe: | c_1 = c_3 Cl: | 4 c_2 = 3 c_3 + 2 c_4 Sn: | c_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_1 = 1 and solve the system of equations for the remaining coefficients: c_1 = 1 c_2 = 3/2 c_3 = 1 c_4 = 3/2 Multiply by the least common denominator, 2, to eliminate fractional coefficients: c_1 = 2 c_2 = 3 c_3 = 2 c_4 = 3 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 Fe + 3 SnCl_4 ⟶ 2 FeCl_3 + 3 SnCl_2

+ ⟶ +

iron + stannic chloride ⟶ iron(III) chloride + stannous chloride

Construct the equilibrium constant, K, expression for: Fe + SnCl_4 ⟶ FeCl_3 + SnCl_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 Fe + 3 SnCl_4 ⟶ 2 FeCl_3 + 3 SnCl_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 Fe | 2 | -2 SnCl_4 | 3 | -3 FeCl_3 | 2 | 2 SnCl_2 | 3 | 3 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Fe | 2 | -2 | ([Fe])^(-2) SnCl_4 | 3 | -3 | ([SnCl4])^(-3) FeCl_3 | 2 | 2 | ([FeCl3])^2 SnCl_2 | 3 | 3 | ([SnCl2])^3 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 = ([Fe])^(-2) ([SnCl4])^(-3) ([FeCl3])^2 ([SnCl2])^3 = (([FeCl3])^2 ([SnCl2])^3)/(([Fe])^2 ([SnCl4])^3)

Construct the rate of reaction expression for: Fe + SnCl_4 ⟶ FeCl_3 + SnCl_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 Fe + 3 SnCl_4 ⟶ 2 FeCl_3 + 3 SnCl_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 Fe | 2 | -2 SnCl_4 | 3 | -3 FeCl_3 | 2 | 2 SnCl_2 | 3 | 3 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 Fe | 2 | -2 | -1/2 (Δ[Fe])/(Δt) SnCl_4 | 3 | -3 | -1/3 (Δ[SnCl4])/(Δt) FeCl_3 | 2 | 2 | 1/2 (Δ[FeCl3])/(Δt) SnCl_2 | 3 | 3 | 1/3 (Δ[SnCl2])/(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[Fe])/(Δt) = -1/3 (Δ[SnCl4])/(Δt) = 1/2 (Δ[FeCl3])/(Δt) = 1/3 (Δ[SnCl2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| iron | stannic chloride | iron(III) chloride | stannous chloride formula | Fe | SnCl_4 | FeCl_3 | SnCl_2 Hill formula | Fe | Cl_4Sn | Cl_3Fe | Cl_2Sn name | iron | stannic chloride | iron(III) chloride | stannous chloride IUPAC name | iron | tetrachlorostannane | trichloroiron | dichlorotin

| iron | stannic chloride | iron(III) chloride | stannous chloride molar mass | 55.845 g/mol | 260.5 g/mol | 162.2 g/mol | 189.6 g/mol phase | solid (at STP) | liquid (at STP) | solid (at STP) | solid (at STP) melting point | 1535 °C | -33 °C | 304 °C | 246 °C boiling point | 2750 °C | 114 °C | | 652 °C density | 7.874 g/cm^3 | 2.226 g/cm^3 | | 3.354 g/cm^3 solubility in water | insoluble | soluble | | dynamic viscosity | | 5.8×10^-4 Pa s (at 60 °C) | | 7 Pa s (at 25 °C) odor | | | | odorless