SO2 + RbOH = H2O + Rb2SO3

SO_2 sulfur dioxide + RbOH rubidium hydroxide ⟶ H_2O water + Rb2SO3

Balance the chemical equation algebraically: SO_2 + RbOH ⟶ H_2O + Rb2SO3 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 SO_2 + c_2 RbOH ⟶ c_3 H_2O + c_4 Rb2SO3 Set the number of atoms in the reactants equal to the number of atoms in the products for O, S, H and Rb: O: | 2 c_1 + c_2 = c_3 + 3 c_4 S: | c_1 = c_4 H: | c_2 = 2 c_3 Rb: | 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 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | SO_2 + 2 RbOH ⟶ H_2O + Rb2SO3

+ ⟶ + Rb2SO3

sulfur dioxide + rubidium hydroxide ⟶ water + Rb2SO3

Construct the equilibrium constant, K, expression for: SO_2 + RbOH ⟶ H_2O + Rb2SO3 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: SO_2 + 2 RbOH ⟶ H_2O + Rb2SO3 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 SO_2 | 1 | -1 RbOH | 2 | -2 H_2O | 1 | 1 Rb2SO3 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression SO_2 | 1 | -1 | ([SO2])^(-1) RbOH | 2 | -2 | ([RbOH])^(-2) H_2O | 1 | 1 | [H2O] Rb2SO3 | 1 | 1 | [Rb2SO3] 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 = ([SO2])^(-1) ([RbOH])^(-2) [H2O] [Rb2SO3] = ([H2O] [Rb2SO3])/([SO2] ([RbOH])^2)

Construct the rate of reaction expression for: SO_2 + RbOH ⟶ H_2O + Rb2SO3 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: SO_2 + 2 RbOH ⟶ H_2O + Rb2SO3 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 SO_2 | 1 | -1 RbOH | 2 | -2 H_2O | 1 | 1 Rb2SO3 | 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 SO_2 | 1 | -1 | -(Δ[SO2])/(Δt) RbOH | 2 | -2 | -1/2 (Δ[RbOH])/(Δt) H_2O | 1 | 1 | (Δ[H2O])/(Δt) Rb2SO3 | 1 | 1 | (Δ[Rb2SO3])/(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[SO2])/(Δt) = -1/2 (Δ[RbOH])/(Δt) = (Δ[H2O])/(Δt) = (Δ[Rb2SO3])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| sulfur dioxide | rubidium hydroxide | water | Rb2SO3 formula | SO_2 | RbOH | H_2O | Rb2SO3 Hill formula | O_2S | HORb | H_2O | O3Rb2S name | sulfur dioxide | rubidium hydroxide | water | IUPAC name | sulfur dioxide | rubidium(+1) cation hydroxide | water |

| sulfur dioxide | rubidium hydroxide | water | Rb2SO3 molar mass | 64.06 g/mol | 102.47 g/mol | 18.015 g/mol | 250.99 g/mol phase | gas (at STP) | solid (at STP) | liquid (at STP) | melting point | -73 °C | 301 °C | 0 °C | boiling point | -10 °C | 1390 °C | 99.9839 °C | density | 0.002619 g/cm^3 (at 25 °C) | 1.74 g/cm^3 | 1 g/cm^3 | solubility in water | | soluble | | surface tension | 0.02859 N/m | | 0.0728 N/m | dynamic viscosity | 1.282×10^-5 Pa s (at 25 °C) | | 8.9×10^-4 Pa s (at 25 °C) | odor | | | odorless |