HCl + C2H5OH = H2O + C2H5Cl

HCl hydrogen chloride + CH_3CH_2OH ethanol ⟶ H_2O water + C_2H_5Cl chloroethane

Balance the chemical equation algebraically: HCl + CH_3CH_2OH ⟶ H_2O + C_2H_5Cl Add stoichiometric coefficients, c_i, to the reactants and products: c_1 HCl + c_2 CH_3CH_2OH ⟶ c_3 H_2O + c_4 C_2H_5Cl Set the number of atoms in the reactants equal to the number of atoms in the products for Cl, H, C and O: Cl: | c_1 = c_4 H: | c_1 + 6 c_2 = 2 c_3 + 5 c_4 C: | 2 c_2 = 2 c_4 O: | c_2 = 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 = 1 c_3 = 1 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | HCl + CH_3CH_2OH ⟶ H_2O + C_2H_5Cl

+ ⟶ +

hydrogen chloride + ethanol ⟶ water + chloroethane

Construct the equilibrium constant, K, expression for: HCl + CH_3CH_2OH ⟶ H_2O + C_2H_5Cl 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: HCl + CH_3CH_2OH ⟶ H_2O + C_2H_5Cl 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 HCl | 1 | -1 CH_3CH_2OH | 1 | -1 H_2O | 1 | 1 C_2H_5Cl | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression HCl | 1 | -1 | ([HCl])^(-1) CH_3CH_2OH | 1 | -1 | ([CH3CH2OH])^(-1) H_2O | 1 | 1 | [H2O] C_2H_5Cl | 1 | 1 | [C2H5Cl] 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 = ([HCl])^(-1) ([CH3CH2OH])^(-1) [H2O] [C2H5Cl] = ([H2O] [C2H5Cl])/([HCl] [CH3CH2OH])

Construct the rate of reaction expression for: HCl + CH_3CH_2OH ⟶ H_2O + C_2H_5Cl 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: HCl + CH_3CH_2OH ⟶ H_2O + C_2H_5Cl 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 HCl | 1 | -1 CH_3CH_2OH | 1 | -1 H_2O | 1 | 1 C_2H_5Cl | 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 HCl | 1 | -1 | -(Δ[HCl])/(Δt) CH_3CH_2OH | 1 | -1 | -(Δ[CH3CH2OH])/(Δt) H_2O | 1 | 1 | (Δ[H2O])/(Δt) C_2H_5Cl | 1 | 1 | (Δ[C2H5Cl])/(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[HCl])/(Δt) = -(Δ[CH3CH2OH])/(Δt) = (Δ[H2O])/(Δt) = (Δ[C2H5Cl])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| hydrogen chloride | ethanol | water | chloroethane formula | HCl | CH_3CH_2OH | H_2O | C_2H_5Cl Hill formula | ClH | C_2H_6O | H_2O | C_2H_5Cl name | hydrogen chloride | ethanol | water | chloroethane