HClO3 = HCl + HClO4

HClO3 ⟶ HCl hydrogen chloride + HClO_4 perchloric acid

Balance the chemical equation algebraically: HClO3 ⟶ HCl + HClO_4 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 HClO3 ⟶ c_2 HCl + c_3 HClO_4 Set the number of atoms in the reactants equal to the number of atoms in the products for H, Cl and O: H: | c_1 = c_2 + c_3 Cl: | c_1 = c_2 + c_3 O: | 3 c_1 = 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_2 = 1 and solve the system of equations for the remaining coefficients: c_1 = 4 c_2 = 1 c_3 = 3 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 4 HClO3 ⟶ HCl + 3 HClO_4

HClO3 ⟶ +

HClO3 ⟶ hydrogen chloride + perchloric acid

Construct the equilibrium constant, K, expression for: HClO3 ⟶ HCl + HClO_4 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: 4 HClO3 ⟶ HCl + 3 HClO_4 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 HClO3 | 4 | -4 HCl | 1 | 1 HClO_4 | 3 | 3 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression HClO3 | 4 | -4 | ([HClO3])^(-4) HCl | 1 | 1 | [HCl] HClO_4 | 3 | 3 | ([HClO4])^3 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 = ([HClO3])^(-4) [HCl] ([HClO4])^3 = ([HCl] ([HClO4])^3)/([HClO3])^4

Construct the rate of reaction expression for: HClO3 ⟶ HCl + HClO_4 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: 4 HClO3 ⟶ HCl + 3 HClO_4 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 HClO3 | 4 | -4 HCl | 1 | 1 HClO_4 | 3 | 3 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 HClO3 | 4 | -4 | -1/4 (Δ[HClO3])/(Δt) HCl | 1 | 1 | (Δ[HCl])/(Δt) HClO_4 | 3 | 3 | 1/3 (Δ[HClO4])/(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 = -1/4 (Δ[HClO3])/(Δt) = (Δ[HCl])/(Δt) = 1/3 (Δ[HClO4])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| HClO3 | hydrogen chloride | perchloric acid formula | HClO3 | HCl | HClO_4 Hill formula | HClO3 | ClH | ClHO_4 name | | hydrogen chloride | perchloric acid

| HClO3 | hydrogen chloride | perchloric acid molar mass | 84.45 g/mol | 36.46 g/mol | 100.5 g/mol phase | | gas (at STP) | liquid (at STP) melting point | | -114.17 °C | -112 °C boiling point | | -85 °C | 90 °C density | | 0.00149 g/cm^3 (at 25 °C) | 1.77 g/cm^3 solubility in water | | miscible | very soluble dynamic viscosity | | | 8×10^-4 Pa s (at 25 °C) odor | | | odorless