Na2SO3 = O2 + SO2 + Na

Na_2SO_3 sodium sulfite ⟶ O_2 oxygen + SO_2 sulfur dioxide + Na sodium

Balance the chemical equation algebraically: Na_2SO_3 ⟶ O_2 + SO_2 + Na Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Na_2SO_3 ⟶ c_2 O_2 + c_3 SO_2 + c_4 Na Set the number of atoms in the reactants equal to the number of atoms in the products for Na, O and S: Na: | 2 c_1 = c_4 O: | 3 c_1 = 2 c_2 + 2 c_3 S: | c_1 = 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 = 2 c_2 = 1 c_3 = 2 c_4 = 4 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 Na_2SO_3 ⟶ O_2 + 2 SO_2 + 4 Na

⟶ + +

sodium sulfite ⟶ oxygen + sulfur dioxide + sodium

| sodium sulfite | oxygen | sulfur dioxide | sodium molecular enthalpy | -1101 kJ/mol | 0 kJ/mol | -296.8 kJ/mol | 0 kJ/mol total enthalpy | -2202 kJ/mol | 0 kJ/mol | -593.6 kJ/mol | 0 kJ/mol | H_initial = -2202 kJ/mol | H_final = -593.6 kJ/mol | | ΔH_rxn^0 | -593.6 kJ/mol - -2202 kJ/mol = 1608 kJ/mol (endothermic) | | |

Construct the equilibrium constant, K, expression for: Na_2SO_3 ⟶ O_2 + SO_2 + Na 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 Na_2SO_3 ⟶ O_2 + 2 SO_2 + 4 Na 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 Na_2SO_3 | 2 | -2 O_2 | 1 | 1 SO_2 | 2 | 2 Na | 4 | 4 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Na_2SO_3 | 2 | -2 | ([Na2SO3])^(-2) O_2 | 1 | 1 | [O2] SO_2 | 2 | 2 | ([SO2])^2 Na | 4 | 4 | ([Na])^4 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 = ([Na2SO3])^(-2) [O2] ([SO2])^2 ([Na])^4 = ([O2] ([SO2])^2 ([Na])^4)/([Na2SO3])^2

Construct the rate of reaction expression for: Na_2SO_3 ⟶ O_2 + SO_2 + Na 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 Na_2SO_3 ⟶ O_2 + 2 SO_2 + 4 Na 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 Na_2SO_3 | 2 | -2 O_2 | 1 | 1 SO_2 | 2 | 2 Na | 4 | 4 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 Na_2SO_3 | 2 | -2 | -1/2 (Δ[Na2SO3])/(Δt) O_2 | 1 | 1 | (Δ[O2])/(Δt) SO_2 | 2 | 2 | 1/2 (Δ[SO2])/(Δt) Na | 4 | 4 | 1/4 (Δ[Na])/(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[Na2SO3])/(Δt) = (Δ[O2])/(Δt) = 1/2 (Δ[SO2])/(Δt) = 1/4 (Δ[Na])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| sodium sulfite | oxygen | sulfur dioxide | sodium formula | Na_2SO_3 | O_2 | SO_2 | Na Hill formula | Na_2O_3S | O_2 | O_2S | Na name | sodium sulfite | oxygen | sulfur dioxide | sodium IUPAC name | disodium sulfite | molecular oxygen | sulfur dioxide | sodium