Input interpretation
H_2SO_4 (sulfuric acid) + Fe(OH)_3 (iron(III) hydroxide) ⟶ H_2O (water) + Fe_2(SO_4)_3·xH_2O (iron(III) sulfate hydrate)
Balanced equation
Balance the chemical equation algebraically: H_2SO_4 + Fe(OH)_3 ⟶ H_2O + Fe_2(SO_4)_3·xH_2O Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_2SO_4 + c_2 Fe(OH)_3 ⟶ c_3 H_2O + 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 H, O, S and Fe: H: | 2 c_1 + 3 c_2 = 2 c_3 O: | 4 c_1 + 3 c_2 = c_3 + 12 c_4 S: | c_1 = 3 c_4 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 H_2SO_4 + 2 Fe(OH)_3 ⟶ 6 H_2O + Fe_2(SO_4)_3·xH_2O
Structures
+ ⟶ +
Names
sulfuric acid + iron(III) hydroxide ⟶ water + iron(III) sulfate hydrate
Equilibrium constant
Construct the equilibrium constant, K, expression for: H_2SO_4 + Fe(OH)_3 ⟶ H_2O + 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 H_2SO_4 + 2 Fe(OH)_3 ⟶ 6 H_2O + 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 H_2SO_4 | 3 | -3 Fe(OH)_3 | 2 | -2 H_2O | 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 H_2SO_4 | 3 | -3 | ([H2SO4])^(-3) Fe(OH)_3 | 2 | -2 | ([Fe(OH)3])^(-2) H_2O | 6 | 6 | ([H2O])^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 = ([H2SO4])^(-3) ([Fe(OH)3])^(-2) ([H2O])^6 [Fe2(SO4)3·xH2O] = (([H2O])^6 [Fe2(SO4)3·xH2O])/(([H2SO4])^3 ([Fe(OH)3])^2)
Rate of reaction
Construct the rate of reaction expression for: H_2SO_4 + Fe(OH)_3 ⟶ H_2O + 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 H_2SO_4 + 2 Fe(OH)_3 ⟶ 6 H_2O + 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 H_2SO_4 | 3 | -3 Fe(OH)_3 | 2 | -2 H_2O | 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 H_2SO_4 | 3 | -3 | -1/3 (Δ[H2SO4])/(Δt) Fe(OH)_3 | 2 | -2 | -1/2 (Δ[Fe(OH)3])/(Δt) H_2O | 6 | 6 | 1/6 (Δ[H2O])/(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[H2SO4])/(Δt) = -1/2 (Δ[Fe(OH)3])/(Δt) = 1/6 (Δ[H2O])/(Δt) = (Δ[Fe2(SO4)3·xH2O])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| sulfuric acid | iron(III) hydroxide | water | iron(III) sulfate hydrate formula | H_2SO_4 | Fe(OH)_3 | H_2O | Fe_2(SO_4)_3·xH_2O Hill formula | H_2O_4S | FeH_3O_3 | H_2O | Fe_2O_12S_3 name | sulfuric acid | iron(III) hydroxide | water | iron(III) sulfate hydrate IUPAC name | sulfuric acid | ferric trihydroxide | water | diferric trisulfate
Substance properties
| sulfuric acid | iron(III) hydroxide | water | iron(III) sulfate hydrate molar mass | 98.07 g/mol | 106.87 g/mol | 18.015 g/mol | 399.9 g/mol phase | liquid (at STP) | | liquid (at STP) | melting point | 10.371 °C | | 0 °C | boiling point | 279.6 °C | | 99.9839 °C | density | 1.8305 g/cm^3 | | 1 g/cm^3 | solubility in water | very soluble | | | slightly soluble surface tension | 0.0735 N/m | | 0.0728 N/m | dynamic viscosity | 0.021 Pa s (at 25 °C) | | 8.9×10^-4 Pa s (at 25 °C) | odor | odorless | | odorless |
Units