Input interpretation
HCl hydrogen chloride + CH_3OH methanol ⟶ H_2O water + CH_3Cl methyl chloride
Balanced equation
Balance the chemical equation algebraically: HCl + CH_3OH ⟶ H_2O + CH_3Cl Add stoichiometric coefficients, c_i, to the reactants and products: c_1 HCl + c_2 CH_3OH ⟶ c_3 H_2O + c_4 CH_3Cl 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 + 4 c_2 = 2 c_3 + 3 c_4 C: | c_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_3OH ⟶ H_2O + CH_3Cl
Structures
+ ⟶ +
Names
hydrogen chloride + methanol ⟶ water + methyl chloride
Reaction thermodynamics
Enthalpy
| hydrogen chloride | methanol | water | methyl chloride molecular enthalpy | -92.3 kJ/mol | -238.7 kJ/mol | -285.8 kJ/mol | -81.9 kJ/mol total enthalpy | -92.3 kJ/mol | -238.7 kJ/mol | -285.8 kJ/mol | -81.9 kJ/mol | H_initial = -331 kJ/mol | | H_final = -367.7 kJ/mol | ΔH_rxn^0 | -367.7 kJ/mol - -331 kJ/mol = -36.77 kJ/mol (exothermic) | | |
Equilibrium constant
Construct the equilibrium constant, K, expression for: HCl + CH_3OH ⟶ H_2O + CH_3Cl 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_3OH ⟶ H_2O + CH_3Cl 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_3OH | 1 | -1 H_2O | 1 | 1 CH_3Cl | 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_3OH | 1 | -1 | ([CH3OH])^(-1) H_2O | 1 | 1 | [H2O] CH_3Cl | 1 | 1 | [CH3Cl] 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) ([CH3OH])^(-1) [H2O] [CH3Cl] = ([H2O] [CH3Cl])/([HCl] [CH3OH])
Rate of reaction
Construct the rate of reaction expression for: HCl + CH_3OH ⟶ H_2O + CH_3Cl 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_3OH ⟶ H_2O + CH_3Cl 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_3OH | 1 | -1 H_2O | 1 | 1 CH_3Cl | 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_3OH | 1 | -1 | -(Δ[CH3OH])/(Δt) H_2O | 1 | 1 | (Δ[H2O])/(Δt) CH_3Cl | 1 | 1 | (Δ[CH3Cl])/(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[CH3OH])/(Δt) = (Δ[H2O])/(Δt) = (Δ[CH3Cl])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)
Chemical names and formulas
| hydrogen chloride | methanol | water | methyl chloride formula | HCl | CH_3OH | H_2O | CH_3Cl Hill formula | ClH | CH_4O | H_2O | CH_3Cl name | hydrogen chloride | methanol | water | methyl chloride IUPAC name | hydrogen chloride | methanol | water | chloromethane