Input interpretation
NaOH (sodium hydroxide) + Fe_2(SO_4)_3·xH_2O (iron(III) sulfate hydrate) ⟶ Na_2SO_4 (sodium sulfate) + Fe(OH)_3 (iron(III) hydroxide)
Balanced equation
Balance the chemical equation algebraically: NaOH + Fe_2(SO_4)_3·xH_2O ⟶ Na_2SO_4 + Fe(OH)_3 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 NaOH + c_2 Fe_2(SO_4)_3·xH_2O ⟶ c_3 Na_2SO_4 + c_4 Fe(OH)_3 Set the number of atoms in the reactants equal to the number of atoms in the products for H, Na, O, Fe and S: H: | c_1 = 3 c_4 Na: | c_1 = 2 c_3 O: | c_1 + 12 c_2 = 4 c_3 + 3 c_4 Fe: | 2 c_2 = c_4 S: | 3 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 = 6 c_2 = 1 c_3 = 3 c_4 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 6 NaOH + Fe_2(SO_4)_3·xH_2O ⟶ 3 Na_2SO_4 + 2 Fe(OH)_3
Structures
+ ⟶ +
Names
sodium hydroxide + iron(III) sulfate hydrate ⟶ sodium sulfate + iron(III) hydroxide
Equilibrium constant
Construct the equilibrium constant, K, expression for: NaOH + Fe_2(SO_4)_3·xH_2O ⟶ Na_2SO_4 + Fe(OH)_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: 6 NaOH + Fe_2(SO_4)_3·xH_2O ⟶ 3 Na_2SO_4 + 2 Fe(OH)_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 NaOH | 6 | -6 Fe_2(SO_4)_3·xH_2O | 1 | -1 Na_2SO_4 | 3 | 3 Fe(OH)_3 | 2 | 2 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression NaOH | 6 | -6 | ([NaOH])^(-6) Fe_2(SO_4)_3·xH_2O | 1 | -1 | ([Fe2(SO4)3·xH2O])^(-1) Na_2SO_4 | 3 | 3 | ([Na2SO4])^3 Fe(OH)_3 | 2 | 2 | ([Fe(OH)3])^2 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 = ([NaOH])^(-6) ([Fe2(SO4)3·xH2O])^(-1) ([Na2SO4])^3 ([Fe(OH)3])^2 = (([Na2SO4])^3 ([Fe(OH)3])^2)/(([NaOH])^6 [Fe2(SO4)3·xH2O])
Rate of reaction
Construct the rate of reaction expression for: NaOH + Fe_2(SO_4)_3·xH_2O ⟶ Na_2SO_4 + Fe(OH)_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: 6 NaOH + Fe_2(SO_4)_3·xH_2O ⟶ 3 Na_2SO_4 + 2 Fe(OH)_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 NaOH | 6 | -6 Fe_2(SO_4)_3·xH_2O | 1 | -1 Na_2SO_4 | 3 | 3 Fe(OH)_3 | 2 | 2 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 NaOH | 6 | -6 | -1/6 (Δ[NaOH])/(Δt) Fe_2(SO_4)_3·xH_2O | 1 | -1 | -(Δ[Fe2(SO4)3·xH2O])/(Δt) Na_2SO_4 | 3 | 3 | 1/3 (Δ[Na2SO4])/(Δt) Fe(OH)_3 | 2 | 2 | 1/2 (Δ[Fe(OH)3])/(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 = -1/6 (Δ[NaOH])/(Δt) = -(Δ[Fe2(SO4)3·xH2O])/(Δt) = 1/3 (Δ[Na2SO4])/(Δt) = 1/2 (Δ[Fe(OH)3])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| sodium hydroxide | iron(III) sulfate hydrate | sodium sulfate | iron(III) hydroxide formula | NaOH | Fe_2(SO_4)_3·xH_2O | Na_2SO_4 | Fe(OH)_3 Hill formula | HNaO | Fe_2O_12S_3 | Na_2O_4S | FeH_3O_3 name | sodium hydroxide | iron(III) sulfate hydrate | sodium sulfate | iron(III) hydroxide IUPAC name | sodium hydroxide | diferric trisulfate | disodium sulfate | ferric trihydroxide
Substance properties
| sodium hydroxide | iron(III) sulfate hydrate | sodium sulfate | iron(III) hydroxide molar mass | 39.997 g/mol | 399.9 g/mol | 142.04 g/mol | 106.87 g/mol phase | solid (at STP) | | solid (at STP) | melting point | 323 °C | | 884 °C | boiling point | 1390 °C | | 1429 °C | density | 2.13 g/cm^3 | | 2.68 g/cm^3 | solubility in water | soluble | slightly soluble | soluble | surface tension | 0.07435 N/m | | | dynamic viscosity | 0.004 Pa s (at 350 °C) | | |
Units