C2H6OH = H2O + H2 + C4H6

C2H6OH ⟶ H_2O water + H_2 hydrogen + CH_2=CHCH=CH_2 1, 3-butadiene

Balance the chemical equation algebraically: C2H6OH ⟶ H_2O + H_2 + CH_2=CHCH=CH_2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 C2H6OH ⟶ c_2 H_2O + c_3 H_2 + c_4 CH_2=CHCH=CH_2 Set the number of atoms in the reactants equal to the number of atoms in the products for C, H and O: C: | 2 c_1 = 4 c_4 H: | 7 c_1 = 2 c_2 + 2 c_3 + 6 c_4 O: | c_1 = c_2 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_4 = 1 and solve the system of equations for the remaining coefficients: c_1 = 2 c_2 = 2 c_3 = 2 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 C2H6OH ⟶ 2 H_2O + 2 H_2 + CH_2=CHCH=CH_2

C2H6OH ⟶ + +

C2H6OH ⟶ water + hydrogen + 1, 3-butadiene

Construct the equilibrium constant, K, expression for: C2H6OH ⟶ H_2O + H_2 + CH_2=CHCH=CH_2 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 C2H6OH ⟶ 2 H_2O + 2 H_2 + CH_2=CHCH=CH_2 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 C2H6OH | 2 | -2 H_2O | 2 | 2 H_2 | 2 | 2 CH_2=CHCH=CH_2 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression C2H6OH | 2 | -2 | ([C2H6OH])^(-2) H_2O | 2 | 2 | ([H2O])^2 H_2 | 2 | 2 | ([H2])^2 CH_2=CHCH=CH_2 | 1 | 1 | [CH2=CHCH=CH2] 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 = ([C2H6OH])^(-2) ([H2O])^2 ([H2])^2 [CH2=CHCH=CH2] = (([H2O])^2 ([H2])^2 [CH2=CHCH=CH2])/([C2H6OH])^2

Construct the rate of reaction expression for: C2H6OH ⟶ H_2O + H_2 + CH_2=CHCH=CH_2 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 C2H6OH ⟶ 2 H_2O + 2 H_2 + CH_2=CHCH=CH_2 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 C2H6OH | 2 | -2 H_2O | 2 | 2 H_2 | 2 | 2 CH_2=CHCH=CH_2 | 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 C2H6OH | 2 | -2 | -1/2 (Δ[C2H6OH])/(Δt) H_2O | 2 | 2 | 1/2 (Δ[H2O])/(Δt) H_2 | 2 | 2 | 1/2 (Δ[H2])/(Δt) CH_2=CHCH=CH_2 | 1 | 1 | (Δ[CH2=CHCH=CH2])/(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[C2H6OH])/(Δt) = 1/2 (Δ[H2O])/(Δt) = 1/2 (Δ[H2])/(Δt) = (Δ[CH2=CHCH=CH2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| C2H6OH | water | hydrogen | 1, 3-butadiene formula | C2H6OH | H_2O | H_2 | CH_2=CHCH=CH_2 Hill formula | C2H7O | H_2O | H_2 | C_4H_6 name | | water | hydrogen | 1, 3-butadiene IUPAC name | | water | molecular hydrogen | buta-1, 3-diene

| C2H6OH | water | hydrogen | 1, 3-butadiene molar mass | 47.08 g/mol | 18.015 g/mol | 2.016 g/mol | 54.09 g/mol phase | | liquid (at STP) | gas (at STP) | gas (at STP) melting point | | 0 °C | -259.2 °C | -109 °C boiling point | | 99.9839 °C | -252.8 °C | -4.5 °C density | | 1 g/cm^3 | 8.99×10^-5 g/cm^3 (at 0 °C) | 0.62 g/cm^3 (at 20 °C) solubility in water | | | | insoluble surface tension | | 0.0728 N/m | | 0.0134 N/m dynamic viscosity | | 8.9×10^-4 Pa s (at 25 °C) | 8.9×10^-6 Pa s (at 25 °C) | 7.54×10^-6 Pa s (at 20 °C) odor | | odorless | odorless |