Input interpretation
HCl hydrogen chloride + Na_2S_2O_3 sodium hyposulfite + KIO_3 potassium iodate ⟶ H_2O water + K_2SO_4 potassium sulfate + Na_2SO_4 sodium sulfate + ICl iodine monochloride
Balanced equation
Balance the chemical equation algebraically: HCl + Na_2S_2O_3 + KIO_3 ⟶ H_2O + K_2SO_4 + Na_2SO_4 + ICl Add stoichiometric coefficients, c_i, to the reactants and products: c_1 HCl + c_2 Na_2S_2O_3 + c_3 KIO_3 ⟶ c_4 H_2O + c_5 K_2SO_4 + c_6 Na_2SO_4 + c_7 ICl Set the number of atoms in the reactants equal to the number of atoms in the products for Cl, H, Na, O, S, I and K: Cl: | c_1 = c_7 H: | c_1 = 2 c_4 Na: | 2 c_2 = 2 c_6 O: | 3 c_2 + 3 c_3 = c_4 + 4 c_5 + 4 c_6 S: | 2 c_2 = c_5 + c_6 I: | c_3 = c_7 K: | c_3 = 2 c_5 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 = 2 c_2 = 1 c_3 = 2 c_4 = 1 c_5 = 1 c_6 = 1 c_7 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 HCl + Na_2S_2O_3 + 2 KIO_3 ⟶ H_2O + K_2SO_4 + Na_2SO_4 + 2 ICl
Structures
+ + ⟶ + + +
Names
hydrogen chloride + sodium hyposulfite + potassium iodate ⟶ water + potassium sulfate + sodium sulfate + iodine monochloride
Equilibrium constant
Construct the equilibrium constant, K, expression for: HCl + Na_2S_2O_3 + KIO_3 ⟶ H_2O + K_2SO_4 + Na_2SO_4 + ICl 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: 2 HCl + Na_2S_2O_3 + 2 KIO_3 ⟶ H_2O + K_2SO_4 + Na_2SO_4 + 2 ICl 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 | 2 | -2 Na_2S_2O_3 | 1 | -1 KIO_3 | 2 | -2 H_2O | 1 | 1 K_2SO_4 | 1 | 1 Na_2SO_4 | 1 | 1 ICl | 2 | 2 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression HCl | 2 | -2 | ([HCl])^(-2) Na_2S_2O_3 | 1 | -1 | ([Na2S2O3])^(-1) KIO_3 | 2 | -2 | ([KIO3])^(-2) H_2O | 1 | 1 | [H2O] K_2SO_4 | 1 | 1 | [K2SO4] Na_2SO_4 | 1 | 1 | [Na2SO4] ICl | 2 | 2 | ([ICl])^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])^(-2) ([Na2S2O3])^(-1) ([KIO3])^(-2) [H2O] [K2SO4] [Na2SO4] ([ICl])^2 = ([H2O] [K2SO4] [Na2SO4] ([ICl])^2)/(([HCl])^2 [Na2S2O3] ([KIO3])^2)
Rate of reaction
Construct the rate of reaction expression for: HCl + Na_2S_2O_3 + KIO_3 ⟶ H_2O + K_2SO_4 + Na_2SO_4 + ICl 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: 2 HCl + Na_2S_2O_3 + 2 KIO_3 ⟶ H_2O + K_2SO_4 + Na_2SO_4 + 2 ICl 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 | 2 | -2 Na_2S_2O_3 | 1 | -1 KIO_3 | 2 | -2 H_2O | 1 | 1 K_2SO_4 | 1 | 1 Na_2SO_4 | 1 | 1 ICl | 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 | 2 | -2 | -1/2 (Δ[HCl])/(Δt) Na_2S_2O_3 | 1 | -1 | -(Δ[Na2S2O3])/(Δt) KIO_3 | 2 | -2 | -1/2 (Δ[KIO3])/(Δt) H_2O | 1 | 1 | (Δ[H2O])/(Δt) K_2SO_4 | 1 | 1 | (Δ[K2SO4])/(Δt) Na_2SO_4 | 1 | 1 | (Δ[Na2SO4])/(Δt) ICl | 2 | 2 | 1/2 (Δ[ICl])/(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 = -1/2 (Δ[HCl])/(Δt) = -(Δ[Na2S2O3])/(Δt) = -1/2 (Δ[KIO3])/(Δt) = (Δ[H2O])/(Δt) = (Δ[K2SO4])/(Δt) = (Δ[Na2SO4])/(Δt) = 1/2 (Δ[ICl])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| hydrogen chloride | sodium hyposulfite | potassium iodate | water | potassium sulfate | sodium sulfate | iodine monochloride formula | HCl | Na_2S_2O_3 | KIO_3 | H_2O | K_2SO_4 | Na_2SO_4 | ICl Hill formula | ClH | Na_2O_3S_2 | IKO_3 | H_2O | K_2O_4S | Na_2O_4S | ClI name | hydrogen chloride | sodium hyposulfite | potassium iodate | water | potassium sulfate | sodium sulfate | iodine monochloride IUPAC name | hydrogen chloride | | potassium iodate | water | dipotassium sulfate | disodium sulfate |