Input interpretation
HCl hydrogen chloride + Fe2S3 ⟶ S mixed sulfur + H_2S hydrogen sulfide + FeCl_2 iron(II) chloride
Balanced equation
Balance the chemical equation algebraically: HCl + Fe2S3 ⟶ S + H_2S + FeCl_2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 HCl + c_2 Fe2S3 ⟶ c_3 S + c_4 H_2S + c_5 FeCl_2 Set the number of atoms in the reactants equal to the number of atoms in the products for Cl, H, Fe and S: Cl: | c_1 = 2 c_5 H: | c_1 = 2 c_4 Fe: | 2 c_2 = c_5 S: | 3 c_2 = c_3 + 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_2 = 1 and solve the system of equations for the remaining coefficients: c_1 = 4 c_2 = 1 c_3 = 1 c_4 = 2 c_5 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 4 HCl + Fe2S3 ⟶ S + 2 H_2S + 2 FeCl_2
Structures
+ Fe2S3 ⟶ + +
Names
hydrogen chloride + Fe2S3 ⟶ mixed sulfur + hydrogen sulfide + iron(II) chloride
Equilibrium constant
Construct the equilibrium constant, K, expression for: HCl + Fe2S3 ⟶ S + H_2S + FeCl_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: 4 HCl + Fe2S3 ⟶ S + 2 H_2S + 2 FeCl_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 HCl | 4 | -4 Fe2S3 | 1 | -1 S | 1 | 1 H_2S | 2 | 2 FeCl_2 | 2 | 2 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression HCl | 4 | -4 | ([HCl])^(-4) Fe2S3 | 1 | -1 | ([Fe2S3])^(-1) S | 1 | 1 | [S] H_2S | 2 | 2 | ([H2S])^2 FeCl_2 | 2 | 2 | ([FeCl2])^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 = ([HCl])^(-4) ([Fe2S3])^(-1) [S] ([H2S])^2 ([FeCl2])^2 = ([S] ([H2S])^2 ([FeCl2])^2)/(([HCl])^4 [Fe2S3])
Rate of reaction
Construct the rate of reaction expression for: HCl + Fe2S3 ⟶ S + H_2S + FeCl_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: 4 HCl + Fe2S3 ⟶ S + 2 H_2S + 2 FeCl_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 HCl | 4 | -4 Fe2S3 | 1 | -1 S | 1 | 1 H_2S | 2 | 2 FeCl_2 | 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 HCl | 4 | -4 | -1/4 (Δ[HCl])/(Δt) Fe2S3 | 1 | -1 | -(Δ[Fe2S3])/(Δt) S | 1 | 1 | (Δ[S])/(Δt) H_2S | 2 | 2 | 1/2 (Δ[H2S])/(Δt) FeCl_2 | 2 | 2 | 1/2 (Δ[FeCl2])/(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[HCl])/(Δt) = -(Δ[Fe2S3])/(Δt) = (Δ[S])/(Δt) = 1/2 (Δ[H2S])/(Δt) = 1/2 (Δ[FeCl2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| hydrogen chloride | Fe2S3 | mixed sulfur | hydrogen sulfide | iron(II) chloride formula | HCl | Fe2S3 | S | H_2S | FeCl_2 Hill formula | ClH | Fe2S3 | S | H_2S | Cl_2Fe name | hydrogen chloride | | mixed sulfur | hydrogen sulfide | iron(II) chloride IUPAC name | hydrogen chloride | | sulfur | hydrogen sulfide | dichloroiron
Substance properties
| hydrogen chloride | Fe2S3 | mixed sulfur | hydrogen sulfide | iron(II) chloride molar mass | 36.46 g/mol | 207.9 g/mol | 32.06 g/mol | 34.08 g/mol | 126.7 g/mol phase | gas (at STP) | | solid (at STP) | gas (at STP) | solid (at STP) melting point | -114.17 °C | | 112.8 °C | -85 °C | 677 °C boiling point | -85 °C | | 444.7 °C | -60 °C | density | 0.00149 g/cm^3 (at 25 °C) | | 2.07 g/cm^3 | 0.001393 g/cm^3 (at 25 °C) | 3.16 g/cm^3 solubility in water | miscible | | | | dynamic viscosity | | | | 1.239×10^-5 Pa s (at 25 °C) |
Units