H2S + NaClO3 = H2SO4 + NaCl

H_2S hydrogen sulfide + NaClO_3 sodium chlorate ⟶ H_2SO_4 sulfuric acid + NaCl sodium chloride

Balance the chemical equation algebraically: H_2S + NaClO_3 ⟶ H_2SO_4 + NaCl Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_2S + c_2 NaClO_3 ⟶ c_3 H_2SO_4 + c_4 NaCl Set the number of atoms in the reactants equal to the number of atoms in the products for H, S, Cl, Na and O: H: | 2 c_1 = 2 c_3 S: | c_1 = c_3 Cl: | c_2 = c_4 Na: | c_2 = c_4 O: | 3 c_2 = 4 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 = 4/3 c_3 = 1 c_4 = 4/3 Multiply by the least common denominator, 3, to eliminate fractional coefficients: c_1 = 3 c_2 = 4 c_3 = 3 c_4 = 4 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 3 H_2S + 4 NaClO_3 ⟶ 3 H_2SO_4 + 4 NaCl

+ ⟶ +

hydrogen sulfide + sodium chlorate ⟶ sulfuric acid + sodium chloride

Construct the equilibrium constant, K, expression for: H_2S + NaClO_3 ⟶ H_2SO_4 + NaCl 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_2S + 4 NaClO_3 ⟶ 3 H_2SO_4 + 4 NaCl 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_2S | 3 | -3 NaClO_3 | 4 | -4 H_2SO_4 | 3 | 3 NaCl | 4 | 4 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression H_2S | 3 | -3 | ([H2S])^(-3) NaClO_3 | 4 | -4 | ([NaClO3])^(-4) H_2SO_4 | 3 | 3 | ([H2SO4])^3 NaCl | 4 | 4 | ([NaCl])^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 = ([H2S])^(-3) ([NaClO3])^(-4) ([H2SO4])^3 ([NaCl])^4 = (([H2SO4])^3 ([NaCl])^4)/(([H2S])^3 ([NaClO3])^4)

Construct the rate of reaction expression for: H_2S + NaClO_3 ⟶ H_2SO_4 + NaCl 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_2S + 4 NaClO_3 ⟶ 3 H_2SO_4 + 4 NaCl 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_2S | 3 | -3 NaClO_3 | 4 | -4 H_2SO_4 | 3 | 3 NaCl | 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 H_2S | 3 | -3 | -1/3 (Δ[H2S])/(Δt) NaClO_3 | 4 | -4 | -1/4 (Δ[NaClO3])/(Δt) H_2SO_4 | 3 | 3 | 1/3 (Δ[H2SO4])/(Δt) NaCl | 4 | 4 | 1/4 (Δ[NaCl])/(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[H2S])/(Δt) = -1/4 (Δ[NaClO3])/(Δt) = 1/3 (Δ[H2SO4])/(Δt) = 1/4 (Δ[NaCl])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| hydrogen sulfide | sodium chlorate | sulfuric acid | sodium chloride formula | H_2S | NaClO_3 | H_2SO_4 | NaCl Hill formula | H_2S | ClNaO_3 | H_2O_4S | ClNa name | hydrogen sulfide | sodium chlorate | sulfuric acid | sodium chloride

| hydrogen sulfide | sodium chlorate | sulfuric acid | sodium chloride molar mass | 34.08 g/mol | 106.4 g/mol | 98.07 g/mol | 58.44 g/mol phase | gas (at STP) | liquid (at STP) | liquid (at STP) | solid (at STP) melting point | -85 °C | | 10.371 °C | 801 °C boiling point | -60 °C | 106 °C | 279.6 °C | 1413 °C density | 0.001393 g/cm^3 (at 25 °C) | 1.3 g/cm^3 | 1.8305 g/cm^3 | 2.16 g/cm^3 solubility in water | | very soluble | very soluble | soluble surface tension | | | 0.0735 N/m | dynamic viscosity | 1.239×10^-5 Pa s (at 25 °C) | 0.00542 Pa s (at 286 °C) | 0.021 Pa s (at 25 °C) | odor | | odorless | odorless | odorless