K2SO3 = K + SO3

K_2SO_3 (potassium sulfite) ⟶ K (potassium) + SO_3 (sulfur trioxide)

Balance the chemical equation algebraically: K_2SO_3 ⟶ K + SO_3 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 K_2SO_3 ⟶ c_2 K + c_3 SO_3 Set the number of atoms in the reactants equal to the number of atoms in the products for K, O and S: K: | 2 c_1 = c_2 O: | 3 c_1 = 3 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_1 = 1 and solve the system of equations for the remaining coefficients: c_1 = 1 c_2 = 2 c_3 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | K_2SO_3 ⟶ 2 K + SO_3

⟶ +

potassium sulfite ⟶ potassium + sulfur trioxide

Construct the equilibrium constant, K, expression for: K_2SO_3 ⟶ K + SO_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: K_2SO_3 ⟶ 2 K + SO_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 K_2SO_3 | 1 | -1 K | 2 | 2 SO_3 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression K_2SO_3 | 1 | -1 | ([K2SO3])^(-1) K | 2 | 2 | ([K])^2 SO_3 | 1 | 1 | [SO3] 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 = ([K2SO3])^(-1) ([K])^2 [SO3] = (([K])^2 [SO3])/([K2SO3])

Construct the rate of reaction expression for: K_2SO_3 ⟶ K + SO_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: K_2SO_3 ⟶ 2 K + SO_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 K_2SO_3 | 1 | -1 K | 2 | 2 SO_3 | 1 | 1 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 K_2SO_3 | 1 | -1 | -(Δ[K2SO3])/(Δt) K | 2 | 2 | 1/2 (Δ[K])/(Δt) SO_3 | 1 | 1 | (Δ[SO3])/(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[K2SO3])/(Δt) = 1/2 (Δ[K])/(Δt) = (Δ[SO3])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| potassium sulfite | potassium | sulfur trioxide formula | K_2SO_3 | K | SO_3 Hill formula | K_2O_3S | K | O_3S name | potassium sulfite | potassium | sulfur trioxide IUPAC name | dipotassium sulfite | potassium | sulfur trioxide

| potassium sulfite | potassium | sulfur trioxide molar mass | 158.25 g/mol | 39.0983 g/mol | 80.06 g/mol phase | | solid (at STP) | liquid (at STP) melting point | | 64 °C | 16.8 °C boiling point | | 760 °C | 44.7 °C density | | 0.86 g/cm^3 | 1.97 g/cm^3 solubility in water | | reacts | reacts dynamic viscosity | | | 0.00159 Pa s (at 30 °C)