Al + HCl3 = H2 + AlCl3

Al aluminum + HCl3 ⟶ H_2 hydrogen + AlCl_3 aluminum chloride

Balance the chemical equation algebraically: Al + HCl3 ⟶ H_2 + AlCl_3 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Al + c_2 HCl3 ⟶ c_3 H_2 + c_4 AlCl_3 Set the number of atoms in the reactants equal to the number of atoms in the products for Al, H and Cl: Al: | c_1 = c_4 H: | c_2 = 2 c_3 Cl: | 3 c_2 = 3 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_3 = 1 and solve the system of equations for the remaining coefficients: c_1 = 2 c_2 = 2 c_3 = 1 c_4 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 Al + 2 HCl3 ⟶ H_2 + 2 AlCl_3

+ HCl3 ⟶ +

aluminum + HCl3 ⟶ hydrogen + aluminum chloride

Construct the equilibrium constant, K, expression for: Al + HCl3 ⟶ H_2 + AlCl_3 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: 2 Al + 2 HCl3 ⟶ H_2 + 2 AlCl_3 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 Al | 2 | -2 HCl3 | 2 | -2 H_2 | 1 | 1 AlCl_3 | 2 | 2 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Al | 2 | -2 | ([Al])^(-2) HCl3 | 2 | -2 | ([HCl3])^(-2) H_2 | 1 | 1 | [H2] AlCl_3 | 2 | 2 | ([AlCl3])^2 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 = ([Al])^(-2) ([HCl3])^(-2) [H2] ([AlCl3])^2 = ([H2] ([AlCl3])^2)/(([Al])^2 ([HCl3])^2)

Construct the rate of reaction expression for: Al + HCl3 ⟶ H_2 + AlCl_3 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: 2 Al + 2 HCl3 ⟶ H_2 + 2 AlCl_3 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 Al | 2 | -2 HCl3 | 2 | -2 H_2 | 1 | 1 AlCl_3 | 2 | 2 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 Al | 2 | -2 | -1/2 (Δ[Al])/(Δt) HCl3 | 2 | -2 | -1/2 (Δ[HCl3])/(Δt) H_2 | 1 | 1 | (Δ[H2])/(Δt) AlCl_3 | 2 | 2 | 1/2 (Δ[AlCl3])/(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 = -1/2 (Δ[Al])/(Δt) = -1/2 (Δ[HCl3])/(Δt) = (Δ[H2])/(Δt) = 1/2 (Δ[AlCl3])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| aluminum | HCl3 | hydrogen | aluminum chloride formula | Al | HCl3 | H_2 | AlCl_3 name | aluminum | | hydrogen | aluminum chloride IUPAC name | aluminum | | molecular hydrogen | trichloroalumane

| aluminum | HCl3 | hydrogen | aluminum chloride molar mass | 26.9815385 g/mol | 107.4 g/mol | 2.016 g/mol | 133.3 g/mol phase | solid (at STP) | | gas (at STP) | solid (at STP) melting point | 660.4 °C | | -259.2 °C | 190 °C boiling point | 2460 °C | | -252.8 °C | density | 2.7 g/cm^3 | | 8.99×10^-5 g/cm^3 (at 0 °C) | solubility in water | insoluble | | | surface tension | 0.817 N/m | | | dynamic viscosity | 1.5×10^-4 Pa s (at 760 °C) | | 8.9×10^-6 Pa s (at 25 °C) | odor | odorless | | odorless |