H2O + FeSO4 = [Fe(H2O)4]SO4

H_2O (water) + FeSO_4 (duretter) ⟶ Fe(H2O)4SO4

Balance the chemical equation algebraically: H_2O + FeSO_4 ⟶ Fe(H2O)4SO4 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_2O + c_2 FeSO_4 ⟶ c_3 Fe(H2O)4SO4 Set the number of atoms in the reactants equal to the number of atoms in the products for H, O, Fe and S: H: | 2 c_1 = 8 c_3 O: | c_1 + 4 c_2 = 8 c_3 Fe: | c_2 = c_3 S: | 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_2 = 1 and solve the system of equations for the remaining coefficients: c_1 = 4 c_2 = 1 c_3 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 4 H_2O + FeSO_4 ⟶ Fe(H2O)4SO4

+ ⟶ Fe(H2O)4SO4

water + duretter ⟶ Fe(H2O)4SO4

Construct the equilibrium constant, K, expression for: H_2O + FeSO_4 ⟶ Fe(H2O)4SO4 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: 4 H_2O + FeSO_4 ⟶ Fe(H2O)4SO4 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 H_2O | 4 | -4 FeSO_4 | 1 | -1 Fe(H2O)4SO4 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression H_2O | 4 | -4 | ([H2O])^(-4) FeSO_4 | 1 | -1 | ([FeSO4])^(-1) Fe(H2O)4SO4 | 1 | 1 | [Fe(H2O)4SO4] 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 = ([H2O])^(-4) ([FeSO4])^(-1) [Fe(H2O)4SO4] = ([Fe(H2O)4SO4])/(([H2O])^4 [FeSO4])

Construct the rate of reaction expression for: H_2O + FeSO_4 ⟶ Fe(H2O)4SO4 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: 4 H_2O + FeSO_4 ⟶ Fe(H2O)4SO4 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 H_2O | 4 | -4 FeSO_4 | 1 | -1 Fe(H2O)4SO4 | 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 H_2O | 4 | -4 | -1/4 (Δ[H2O])/(Δt) FeSO_4 | 1 | -1 | -(Δ[FeSO4])/(Δt) Fe(H2O)4SO4 | 1 | 1 | (Δ[Fe(H2O)4SO4])/(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 = -1/4 (Δ[H2O])/(Δt) = -(Δ[FeSO4])/(Δt) = (Δ[Fe(H2O)4SO4])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| water | duretter | Fe(H2O)4SO4 formula | H_2O | FeSO_4 | Fe(H2O)4SO4 Hill formula | H_2O | FeO_4S | H8FeO8S name | water | duretter | IUPAC name | water | iron(+2) cation sulfate |

| water | duretter | Fe(H2O)4SO4 molar mass | 18.015 g/mol | 151.9 g/mol | 223.96 g/mol phase | liquid (at STP) | | melting point | 0 °C | | boiling point | 99.9839 °C | | density | 1 g/cm^3 | 2.841 g/cm^3 | surface tension | 0.0728 N/m | | dynamic viscosity | 8.9×10^-4 Pa s (at 25 °C) | | odor | odorless | |