Input interpretation
Fe_2(SO_4)_3·xH_2O iron(III) sulfate hydrate + NaI sodium iodide ⟶ I_2 iodine + Na_2SO_4 sodium sulfate + FeSO_4 duretter
Balanced equation
Balance the chemical equation algebraically: Fe_2(SO_4)_3·xH_2O + NaI ⟶ I_2 + Na_2SO_4 + FeSO_4 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Fe_2(SO_4)_3·xH_2O + c_2 NaI ⟶ c_3 I_2 + c_4 Na_2SO_4 + c_5 FeSO_4 Set the number of atoms in the reactants equal to the number of atoms in the products for Fe, O, S, I and Na: Fe: | 2 c_1 = c_5 O: | 12 c_1 = 4 c_4 + 4 c_5 S: | 3 c_1 = c_4 + c_5 I: | c_2 = 2 c_3 Na: | 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_1 = 1 and solve the system of equations for the remaining coefficients: c_1 = 1 c_2 = 2 c_3 = 1 c_4 = 1 c_5 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | Fe_2(SO_4)_3·xH_2O + 2 NaI ⟶ I_2 + Na_2SO_4 + 2 FeSO_4
Structures
+ ⟶ + +
Names
iron(III) sulfate hydrate + sodium iodide ⟶ iodine + sodium sulfate + duretter
Equilibrium constant
Construct the equilibrium constant, K, expression for: Fe_2(SO_4)_3·xH_2O + NaI ⟶ I_2 + Na_2SO_4 + FeSO_4 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: Fe_2(SO_4)_3·xH_2O + 2 NaI ⟶ I_2 + Na_2SO_4 + 2 FeSO_4 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(SO_4)_3·xH_2O | 1 | -1 NaI | 2 | -2 I_2 | 1 | 1 Na_2SO_4 | 1 | 1 FeSO_4 | 2 | 2 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Fe_2(SO_4)_3·xH_2O | 1 | -1 | ([Fe2(SO4)3·xH2O])^(-1) NaI | 2 | -2 | ([NaI])^(-2) I_2 | 1 | 1 | [I2] Na_2SO_4 | 1 | 1 | [Na2SO4] FeSO_4 | 2 | 2 | ([FeSO4])^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 = ([Fe2(SO4)3·xH2O])^(-1) ([NaI])^(-2) [I2] [Na2SO4] ([FeSO4])^2 = ([I2] [Na2SO4] ([FeSO4])^2)/([Fe2(SO4)3·xH2O] ([NaI])^2)
Rate of reaction
Construct the rate of reaction expression for: Fe_2(SO_4)_3·xH_2O + NaI ⟶ I_2 + Na_2SO_4 + FeSO_4 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: Fe_2(SO_4)_3·xH_2O + 2 NaI ⟶ I_2 + Na_2SO_4 + 2 FeSO_4 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(SO_4)_3·xH_2O | 1 | -1 NaI | 2 | -2 I_2 | 1 | 1 Na_2SO_4 | 1 | 1 FeSO_4 | 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 Fe_2(SO_4)_3·xH_2O | 1 | -1 | -(Δ[Fe2(SO4)3·xH2O])/(Δt) NaI | 2 | -2 | -1/2 (Δ[NaI])/(Δt) I_2 | 1 | 1 | (Δ[I2])/(Δt) Na_2SO_4 | 1 | 1 | (Δ[Na2SO4])/(Δt) FeSO_4 | 2 | 2 | 1/2 (Δ[FeSO4])/(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 = -(Δ[Fe2(SO4)3·xH2O])/(Δt) = -1/2 (Δ[NaI])/(Δt) = (Δ[I2])/(Δt) = (Δ[Na2SO4])/(Δt) = 1/2 (Δ[FeSO4])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| iron(III) sulfate hydrate | sodium iodide | iodine | sodium sulfate | duretter formula | Fe_2(SO_4)_3·xH_2O | NaI | I_2 | Na_2SO_4 | FeSO_4 Hill formula | Fe_2O_12S_3 | INa | I_2 | Na_2O_4S | FeO_4S name | iron(III) sulfate hydrate | sodium iodide | iodine | sodium sulfate | duretter IUPAC name | diferric trisulfate | sodium iodide | molecular iodine | disodium sulfate | iron(+2) cation sulfate
Substance properties
| iron(III) sulfate hydrate | sodium iodide | iodine | sodium sulfate | duretter molar mass | 399.9 g/mol | 149.89424 g/mol | 253.80894 g/mol | 142.04 g/mol | 151.9 g/mol phase | | solid (at STP) | solid (at STP) | solid (at STP) | melting point | | 661 °C | 113 °C | 884 °C | boiling point | | 1300 °C | 184 °C | 1429 °C | density | | 3.67 g/cm^3 | 4.94 g/cm^3 | 2.68 g/cm^3 | 2.841 g/cm^3 solubility in water | slightly soluble | | | soluble | dynamic viscosity | | 0.0010446 Pa s (at 691 °C) | 0.00227 Pa s (at 116 °C) | |
Units