Cl2 + NaOH = NaCl + HClO

Cl_2 chlorine + NaOH sodium hydroxide ⟶ NaCl sodium chloride + HOCl hypochlorous acid

Balance the chemical equation algebraically: Cl_2 + NaOH ⟶ NaCl + HOCl Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Cl_2 + c_2 NaOH ⟶ c_3 NaCl + c_4 HOCl Set the number of atoms in the reactants equal to the number of atoms in the products for Cl, H, Na and O: Cl: | 2 c_1 = c_3 + c_4 H: | c_2 = c_4 Na: | c_2 = c_3 O: | 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_1 = 1 and solve the system of equations for the remaining coefficients: c_1 = 1 c_2 = 1 c_3 = 1 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | Cl_2 + NaOH ⟶ NaCl + HOCl

+ ⟶ +

chlorine + sodium hydroxide ⟶ sodium chloride + hypochlorous acid

Construct the equilibrium constant, K, expression for: Cl_2 + NaOH ⟶ NaCl + HOCl 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: Cl_2 + NaOH ⟶ NaCl + HOCl 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 Cl_2 | 1 | -1 NaOH | 1 | -1 NaCl | 1 | 1 HOCl | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Cl_2 | 1 | -1 | ([Cl2])^(-1) NaOH | 1 | -1 | ([NaOH])^(-1) NaCl | 1 | 1 | [NaCl] HOCl | 1 | 1 | [HOCl] 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 = ([Cl2])^(-1) ([NaOH])^(-1) [NaCl] [HOCl] = ([NaCl] [HOCl])/([Cl2] [NaOH])

Construct the rate of reaction expression for: Cl_2 + NaOH ⟶ NaCl + HOCl 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: Cl_2 + NaOH ⟶ NaCl + HOCl 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 Cl_2 | 1 | -1 NaOH | 1 | -1 NaCl | 1 | 1 HOCl | 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 Cl_2 | 1 | -1 | -(Δ[Cl2])/(Δt) NaOH | 1 | -1 | -(Δ[NaOH])/(Δt) NaCl | 1 | 1 | (Δ[NaCl])/(Δt) HOCl | 1 | 1 | (Δ[HOCl])/(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[Cl2])/(Δt) = -(Δ[NaOH])/(Δt) = (Δ[NaCl])/(Δt) = (Δ[HOCl])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| chlorine | sodium hydroxide | sodium chloride | hypochlorous acid formula | Cl_2 | NaOH | NaCl | HOCl Hill formula | Cl_2 | HNaO | ClNa | ClHO name | chlorine | sodium hydroxide | sodium chloride | hypochlorous acid IUPAC name | molecular chlorine | sodium hydroxide | sodium chloride | hypochlorous acid

| chlorine | sodium hydroxide | sodium chloride | hypochlorous acid molar mass | 70.9 g/mol | 39.997 g/mol | 58.44 g/mol | 52.46 g/mol phase | gas (at STP) | solid (at STP) | solid (at STP) | melting point | -101 °C | 323 °C | 801 °C | boiling point | -34 °C | 1390 °C | 1413 °C | density | 0.003214 g/cm^3 (at 0 °C) | 2.13 g/cm^3 | 2.16 g/cm^3 | solubility in water | | soluble | soluble | soluble surface tension | | 0.07435 N/m | | dynamic viscosity | | 0.004 Pa s (at 350 °C) | | odor | | | odorless |