C + MgO = CO2 + Mg

C activated charcoal + MgO magnesium oxide ⟶ CO_2 carbon dioxide + Mg magnesium

Balance the chemical equation algebraically: C + MgO ⟶ CO_2 + Mg Add stoichiometric coefficients, c_i, to the reactants and products: c_1 C + c_2 MgO ⟶ c_3 CO_2 + c_4 Mg Set the number of atoms in the reactants equal to the number of atoms in the products for C, Mg and O: C: | c_1 = c_3 Mg: | c_2 = c_4 O: | c_2 = 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 = 2 c_3 = 1 c_4 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | C + 2 MgO ⟶ CO_2 + 2 Mg

+ ⟶ +

activated charcoal + magnesium oxide ⟶ carbon dioxide + magnesium

Construct the equilibrium constant, K, expression for: C + MgO ⟶ CO_2 + Mg 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: C + 2 MgO ⟶ CO_2 + 2 Mg 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 C | 1 | -1 MgO | 2 | -2 CO_2 | 1 | 1 Mg | 2 | 2 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression C | 1 | -1 | ([C])^(-1) MgO | 2 | -2 | ([MgO])^(-2) CO_2 | 1 | 1 | [CO2] Mg | 2 | 2 | ([Mg])^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 = ([C])^(-1) ([MgO])^(-2) [CO2] ([Mg])^2 = ([CO2] ([Mg])^2)/([C] ([MgO])^2)

Construct the rate of reaction expression for: C + MgO ⟶ CO_2 + Mg 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: C + 2 MgO ⟶ CO_2 + 2 Mg 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 C | 1 | -1 MgO | 2 | -2 CO_2 | 1 | 1 Mg | 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 C | 1 | -1 | -(Δ[C])/(Δt) MgO | 2 | -2 | -1/2 (Δ[MgO])/(Δt) CO_2 | 1 | 1 | (Δ[CO2])/(Δt) Mg | 2 | 2 | 1/2 (Δ[Mg])/(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[C])/(Δt) = -1/2 (Δ[MgO])/(Δt) = (Δ[CO2])/(Δt) = 1/2 (Δ[Mg])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| activated charcoal | magnesium oxide | carbon dioxide | magnesium formula | C | MgO | CO_2 | Mg name | activated charcoal | magnesium oxide | carbon dioxide | magnesium IUPAC name | carbon | oxomagnesium | carbon dioxide | magnesium

| activated charcoal | magnesium oxide | carbon dioxide | magnesium molar mass | 12.011 g/mol | 40.304 g/mol | 44.009 g/mol | 24.305 g/mol phase | solid (at STP) | solid (at STP) | gas (at STP) | solid (at STP) melting point | 3550 °C | 2852 °C | -56.56 °C (at triple point) | 648 °C boiling point | 4027 °C | 3600 °C | -78.5 °C (at sublimation point) | 1090 °C density | 2.26 g/cm^3 | 3.58 g/cm^3 | 0.00184212 g/cm^3 (at 20 °C) | 1.738 g/cm^3 solubility in water | insoluble | | | reacts dynamic viscosity | | | 1.491×10^-5 Pa s (at 25 °C) | odor | | odorless | odorless |