H2O + SO2 + NaIO3 = H2SO4 + NaI

H_2O (water) + SO_2 (sulfur dioxide) + NaIO_3 (sodium iodate) ⟶ H_2SO_4 (sulfuric acid) + NaI (sodium iodide)

Balance the chemical equation algebraically: H_2O + SO_2 + NaIO_3 ⟶ H_2SO_4 + NaI Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_2O + c_2 SO_2 + c_3 NaIO_3 ⟶ c_4 H_2SO_4 + c_5 NaI Set the number of atoms in the reactants equal to the number of atoms in the products for H, O, S, I and Na: H: | 2 c_1 = 2 c_4 O: | c_1 + 2 c_2 + 3 c_3 = 4 c_4 S: | c_2 = c_4 I: | c_3 = c_5 Na: | c_3 = 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_3 = 1 and solve the system of equations for the remaining coefficients: c_1 = 3 c_2 = 3 c_3 = 1 c_4 = 3 c_5 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 3 H_2O + 3 SO_2 + NaIO_3 ⟶ 3 H_2SO_4 + NaI

+ + ⟶ +

water + sulfur dioxide + sodium iodate ⟶ sulfuric acid + sodium iodide

| water | sulfur dioxide | sodium iodate | sulfuric acid | sodium iodide molecular enthalpy | -285.8 kJ/mol | -296.8 kJ/mol | -481.8 kJ/mol | -814 kJ/mol | -287.8 kJ/mol total enthalpy | -857.5 kJ/mol | -890.4 kJ/mol | -481.8 kJ/mol | -2442 kJ/mol | -287.8 kJ/mol | H_initial = -2230 kJ/mol | | | H_final = -2730 kJ/mol | ΔH_rxn^0 | -2730 kJ/mol - -2230 kJ/mol = -500.1 kJ/mol (exothermic) | | | |

Construct the equilibrium constant, K, expression for: H_2O + SO_2 + NaIO_3 ⟶ H_2SO_4 + NaI 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: 3 H_2O + 3 SO_2 + NaIO_3 ⟶ 3 H_2SO_4 + NaI 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 H_2O | 3 | -3 SO_2 | 3 | -3 NaIO_3 | 1 | -1 H_2SO_4 | 3 | 3 NaI | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression H_2O | 3 | -3 | ([H2O])^(-3) SO_2 | 3 | -3 | ([SO2])^(-3) NaIO_3 | 1 | -1 | ([NaIO3])^(-1) H_2SO_4 | 3 | 3 | ([H2SO4])^3 NaI | 1 | 1 | [NaI] 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 = ([H2O])^(-3) ([SO2])^(-3) ([NaIO3])^(-1) ([H2SO4])^3 [NaI] = (([H2SO4])^3 [NaI])/(([H2O])^3 ([SO2])^3 [NaIO3])

Construct the rate of reaction expression for: H_2O + SO_2 + NaIO_3 ⟶ H_2SO_4 + NaI 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: 3 H_2O + 3 SO_2 + NaIO_3 ⟶ 3 H_2SO_4 + NaI 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 H_2O | 3 | -3 SO_2 | 3 | -3 NaIO_3 | 1 | -1 H_2SO_4 | 3 | 3 NaI | 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 H_2O | 3 | -3 | -1/3 (Δ[H2O])/(Δt) SO_2 | 3 | -3 | -1/3 (Δ[SO2])/(Δt) NaIO_3 | 1 | -1 | -(Δ[NaIO3])/(Δt) H_2SO_4 | 3 | 3 | 1/3 (Δ[H2SO4])/(Δt) NaI | 1 | 1 | (Δ[NaI])/(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 = -1/3 (Δ[H2O])/(Δt) = -1/3 (Δ[SO2])/(Δt) = -(Δ[NaIO3])/(Δt) = 1/3 (Δ[H2SO4])/(Δt) = (Δ[NaI])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| water | sulfur dioxide | sodium iodate | sulfuric acid | sodium iodide formula | H_2O | SO_2 | NaIO_3 | H_2SO_4 | NaI Hill formula | H_2O | O_2S | INaO_3 | H_2O_4S | INa name | water | sulfur dioxide | sodium iodate | sulfuric acid | sodium iodide

| water | sulfur dioxide | sodium iodate | sulfuric acid | sodium iodide molar mass | 18.015 g/mol | 64.06 g/mol | 197.891 g/mol | 98.07 g/mol | 149.89424 g/mol phase | liquid (at STP) | gas (at STP) | solid (at STP) | liquid (at STP) | solid (at STP) melting point | 0 °C | -73 °C | 425 °C | 10.371 °C | 661 °C boiling point | 99.9839 °C | -10 °C | | 279.6 °C | 1300 °C density | 1 g/cm^3 | 0.002619 g/cm^3 (at 25 °C) | 3.56 g/cm^3 | 1.8305 g/cm^3 | 3.67 g/cm^3 solubility in water | | | | very soluble | surface tension | 0.0728 N/m | 0.02859 N/m | | 0.0735 N/m | dynamic viscosity | 8.9×10^-4 Pa s (at 25 °C) | 1.282×10^-5 Pa s (at 25 °C) | | 0.021 Pa s (at 25 °C) | 0.0010446 Pa s (at 691 °C) odor | odorless | | | odorless |