NO2 + CO = CO2 + NO

NO_2 nitrogen dioxide + CO carbon monoxide ⟶ CO_2 carbon dioxide + NO nitric oxide

Balance the chemical equation algebraically: NO_2 + CO ⟶ CO_2 + NO Add stoichiometric coefficients, c_i, to the reactants and products: c_1 NO_2 + c_2 CO ⟶ c_3 CO_2 + c_4 NO Set the number of atoms in the reactants equal to the number of atoms in the products for N, O and C: N: | c_1 = c_4 O: | 2 c_1 + c_2 = 2 c_3 + c_4 C: | c_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 = 1 c_3 = 1 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | NO_2 + CO ⟶ CO_2 + NO

+ ⟶ +

nitrogen dioxide + carbon monoxide ⟶ carbon dioxide + nitric oxide

| nitrogen dioxide | carbon monoxide | carbon dioxide | nitric oxide molecular enthalpy | 33.2 kJ/mol | -110.5 kJ/mol | -393.5 kJ/mol | 91.3 kJ/mol total enthalpy | 33.2 kJ/mol | -110.5 kJ/mol | -393.5 kJ/mol | 91.3 kJ/mol | H_initial = -77.3 kJ/mol | | H_final = -302.2 kJ/mol | ΔH_rxn^0 | -302.2 kJ/mol - -77.3 kJ/mol = -224.9 kJ/mol (exothermic) | | |

| nitrogen dioxide | carbon monoxide | carbon dioxide | nitric oxide molecular free energy | 51.3 kJ/mol | -137 kJ/mol | -394.4 kJ/mol | 87.6 kJ/mol total free energy | 51.3 kJ/mol | -137 kJ/mol | -394.4 kJ/mol | 87.6 kJ/mol | G_initial = -85.7 kJ/mol | | G_final = -306.8 kJ/mol | ΔG_rxn^0 | -306.8 kJ/mol - -85.7 kJ/mol = -221.1 kJ/mol (exergonic) | | |

| nitrogen dioxide | carbon monoxide | carbon dioxide | nitric oxide molecular entropy | 240 J/(mol K) | 198 J/(mol K) | 214 J/(mol K) | 211 J/(mol K) total entropy | 240 J/(mol K) | 198 J/(mol K) | 214 J/(mol K) | 211 J/(mol K) | S_initial = 438 J/(mol K) | | S_final = 425 J/(mol K) | ΔS_rxn^0 | 425 J/(mol K) - 438 J/(mol K) = -13 J/(mol K) (exoentropic) | | |

Construct the equilibrium constant, K, expression for: NO_2 + CO ⟶ CO_2 + NO 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: NO_2 + CO ⟶ CO_2 + NO 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 NO_2 | 1 | -1 CO | 1 | -1 CO_2 | 1 | 1 NO | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression NO_2 | 1 | -1 | ([NO2])^(-1) CO | 1 | -1 | ([CO])^(-1) CO_2 | 1 | 1 | [CO2] NO | 1 | 1 | [NO] 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 = ([NO2])^(-1) ([CO])^(-1) [CO2] [NO] = ([CO2] [NO])/([NO2] [CO])

Construct the rate of reaction expression for: NO_2 + CO ⟶ CO_2 + NO 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: NO_2 + CO ⟶ CO_2 + NO 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 NO_2 | 1 | -1 CO | 1 | -1 CO_2 | 1 | 1 NO | 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 NO_2 | 1 | -1 | -(Δ[NO2])/(Δt) CO | 1 | -1 | -(Δ[CO])/(Δt) CO_2 | 1 | 1 | (Δ[CO2])/(Δt) NO | 1 | 1 | (Δ[NO])/(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[NO2])/(Δt) = -(Δ[CO])/(Δt) = (Δ[CO2])/(Δt) = (Δ[NO])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| nitrogen dioxide | carbon monoxide | carbon dioxide | nitric oxide formula | NO_2 | CO | CO_2 | NO name | nitrogen dioxide | carbon monoxide | carbon dioxide | nitric oxide IUPAC name | Nitrogen dioxide | carbon monoxide | carbon dioxide | nitric oxide