CO2 + Zn = CO + ZnO

CO_2 carbon dioxide + Zn zinc ⟶ CO carbon monoxide + ZnO zinc oxide

Balance the chemical equation algebraically: CO_2 + Zn ⟶ CO + ZnO Add stoichiometric coefficients, c_i, to the reactants and products: c_1 CO_2 + c_2 Zn ⟶ c_3 CO + c_4 ZnO Set the number of atoms in the reactants equal to the number of atoms in the products for C, O and Zn: C: | c_1 = c_3 O: | 2 c_1 = c_3 + c_4 Zn: | 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: | | CO_2 + Zn ⟶ CO + ZnO

+ ⟶ +

carbon dioxide + zinc ⟶ carbon monoxide + zinc oxide

| carbon dioxide | zinc | carbon monoxide | zinc oxide molecular enthalpy | -393.5 kJ/mol | 0 kJ/mol | -110.5 kJ/mol | -350.5 kJ/mol total enthalpy | -393.5 kJ/mol | 0 kJ/mol | -110.5 kJ/mol | -350.5 kJ/mol | H_initial = -393.5 kJ/mol | | H_final = -461 kJ/mol | ΔH_rxn^0 | -461 kJ/mol - -393.5 kJ/mol = -67.5 kJ/mol (exothermic) | | |

| carbon dioxide | zinc | carbon monoxide | zinc oxide molecular entropy | 214 J/(mol K) | 42 J/(mol K) | 198 J/(mol K) | 44 J/(mol K) total entropy | 214 J/(mol K) | 42 J/(mol K) | 198 J/(mol K) | 44 J/(mol K) | S_initial = 256 J/(mol K) | | S_final = 242 J/(mol K) | ΔS_rxn^0 | 242 J/(mol K) - 256 J/(mol K) = -14 J/(mol K) (exoentropic) | | |

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

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

| carbon dioxide | zinc | carbon monoxide | zinc oxide formula | CO_2 | Zn | CO | ZnO Hill formula | CO_2 | Zn | CO | OZn name | carbon dioxide | zinc | carbon monoxide | zinc oxide IUPAC name | carbon dioxide | zinc | carbon monoxide | oxozinc

| carbon dioxide | zinc | carbon monoxide | zinc oxide molar mass | 44.009 g/mol | 65.38 g/mol | 28.01 g/mol | 81.38 g/mol phase | gas (at STP) | solid (at STP) | gas (at STP) | solid (at STP) melting point | -56.56 °C (at triple point) | 420 °C | -205 °C | 1975 °C boiling point | -78.5 °C (at sublimation point) | 907 °C | -191.5 °C | 2360 °C density | 0.00184212 g/cm^3 (at 20 °C) | 7.14 g/cm^3 | 0.001145 g/cm^3 (at 25 °C) | 5.6 g/cm^3 solubility in water | | insoluble | | dynamic viscosity | 1.491×10^-5 Pa s (at 25 °C) | | 1.772×10^-5 Pa s (at 25 °C) | odor | odorless | odorless | odorless | odorless