H2O + C = H2 + CO

H_2O (water) + C (activated charcoal) ⟶ H_2 (hydrogen) + CO (carbon monoxide)

Balance the chemical equation algebraically: H_2O + C ⟶ H_2 + CO Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_2O + c_2 C ⟶ c_3 H_2 + c_4 CO Set the number of atoms in the reactants equal to the number of atoms in the products for H, O and C: H: | 2 c_1 = 2 c_3 O: | c_1 = c_4 C: | 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: | | H_2O + C ⟶ H_2 + CO

+ ⟶ +

water + activated charcoal ⟶ hydrogen + carbon monoxide

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

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

| water | activated charcoal | hydrogen | carbon monoxide formula | H_2O | C | H_2 | CO name | water | activated charcoal | hydrogen | carbon monoxide IUPAC name | water | carbon | molecular hydrogen | carbon monoxide

| water | activated charcoal | hydrogen | carbon monoxide molar mass | 18.015 g/mol | 12.011 g/mol | 2.016 g/mol | 28.01 g/mol phase | liquid (at STP) | solid (at STP) | gas (at STP) | gas (at STP) melting point | 0 °C | 3550 °C | -259.2 °C | -205 °C boiling point | 99.9839 °C | 4027 °C | -252.8 °C | -191.5 °C density | 1 g/cm^3 | 2.26 g/cm^3 | 8.99×10^-5 g/cm^3 (at 0 °C) | 0.001145 g/cm^3 (at 25 °C) solubility in water | | insoluble | | surface tension | 0.0728 N/m | | | dynamic viscosity | 8.9×10^-4 Pa s (at 25 °C) | | 8.9×10^-6 Pa s (at 25 °C) | 1.772×10^-5 Pa s (at 25 °C) odor | odorless | | odorless | odorless