NaOH + C6H5SO3H = H2O + Na2SO3 + C6H5OH

NaOH sodium hydroxide + C_6H_5SO_3H benzenesulfonic acid ⟶ H_2O water + Na_2SO_3 sodium sulfite + C_6H_5OH phenol

Balance the chemical equation algebraically: NaOH + C_6H_5SO_3H ⟶ H_2O + Na_2SO_3 + C_6H_5OH Add stoichiometric coefficients, c_i, to the reactants and products: c_1 NaOH + c_2 C_6H_5SO_3H ⟶ c_3 H_2O + c_4 Na_2SO_3 + c_5 C_6H_5OH Set the number of atoms in the reactants equal to the number of atoms in the products for H, Na, O, C and S: H: | c_1 + 6 c_2 = 2 c_3 + 6 c_5 Na: | c_1 = 2 c_4 O: | c_1 + 3 c_2 = c_3 + 3 c_4 + c_5 C: | 6 c_2 = 6 c_5 S: | c_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_2 = 1 and solve the system of equations for the remaining coefficients: c_1 = 2 c_2 = 1 c_3 = 1 c_4 = 1 c_5 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 NaOH + C_6H_5SO_3H ⟶ H_2O + Na_2SO_3 + C_6H_5OH

+ ⟶ + +

sodium hydroxide + benzenesulfonic acid ⟶ water + sodium sulfite + phenol

Construct the equilibrium constant, K, expression for: NaOH + C_6H_5SO_3H ⟶ H_2O + Na_2SO_3 + C_6H_5OH 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 NaOH + C_6H_5SO_3H ⟶ H_2O + Na_2SO_3 + C_6H_5OH 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 NaOH | 2 | -2 C_6H_5SO_3H | 1 | -1 H_2O | 1 | 1 Na_2SO_3 | 1 | 1 C_6H_5OH | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression NaOH | 2 | -2 | ([NaOH])^(-2) C_6H_5SO_3H | 1 | -1 | ([C6H5SO3H])^(-1) H_2O | 1 | 1 | [H2O] Na_2SO_3 | 1 | 1 | [Na2SO3] C_6H_5OH | 1 | 1 | [C6H5OH] 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 = ([NaOH])^(-2) ([C6H5SO3H])^(-1) [H2O] [Na2SO3] [C6H5OH] = ([H2O] [Na2SO3] [C6H5OH])/(([NaOH])^2 [C6H5SO3H])

Construct the rate of reaction expression for: NaOH + C_6H_5SO_3H ⟶ H_2O + Na_2SO_3 + C_6H_5OH 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 NaOH + C_6H_5SO_3H ⟶ H_2O + Na_2SO_3 + C_6H_5OH 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 NaOH | 2 | -2 C_6H_5SO_3H | 1 | -1 H_2O | 1 | 1 Na_2SO_3 | 1 | 1 C_6H_5OH | 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 NaOH | 2 | -2 | -1/2 (Δ[NaOH])/(Δt) C_6H_5SO_3H | 1 | -1 | -(Δ[C6H5SO3H])/(Δt) H_2O | 1 | 1 | (Δ[H2O])/(Δt) Na_2SO_3 | 1 | 1 | (Δ[Na2SO3])/(Δt) C_6H_5OH | 1 | 1 | (Δ[C6H5OH])/(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[NaOH])/(Δt) = -(Δ[C6H5SO3H])/(Δt) = (Δ[H2O])/(Δt) = (Δ[Na2SO3])/(Δt) = (Δ[C6H5OH])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| sodium hydroxide | benzenesulfonic acid | water | sodium sulfite | phenol formula | NaOH | C_6H_5SO_3H | H_2O | Na_2SO_3 | C_6H_5OH Hill formula | HNaO | C_6H_6O_3S | H_2O | Na_2O_3S | C_6H_6O name | sodium hydroxide | benzenesulfonic acid | water | sodium sulfite | phenol IUPAC name | sodium hydroxide | benzenesulfonic acid | water | disodium sulfite | phenol

| sodium hydroxide | benzenesulfonic acid | water | sodium sulfite | phenol molar mass | 39.997 g/mol | 158.2 g/mol | 18.015 g/mol | 126.04 g/mol | 94.11 g/mol phase | solid (at STP) | solid (at STP) | liquid (at STP) | solid (at STP) | solid (at STP) melting point | 323 °C | 50 °C | 0 °C | 500 °C | 40.89 °C boiling point | 1390 °C | 319 °C | 99.9839 °C | | 181.87 °C density | 2.13 g/cm^3 | 1.32 g/cm^3 | 1 g/cm^3 | 2.63 g/cm^3 | 1.071 g/cm^3 solubility in water | soluble | very soluble | | | surface tension | 0.07435 N/m | | 0.0728 N/m | | 0.0382 N/m dynamic viscosity | 0.004 Pa s (at 350 °C) | | 8.9×10^-4 Pa s (at 25 °C) | | -0.7771 Pa s (at 25 °C) odor | | | odorless | |