O2 + Na2O = NaO

O_2 oxygen + Na_2O sodium oxide ⟶ NaO

Balance the chemical equation algebraically: O_2 + Na_2O ⟶ NaO Add stoichiometric coefficients, c_i, to the reactants and products: c_1 O_2 + c_2 Na_2O ⟶ c_3 NaO Set the number of atoms in the reactants equal to the number of atoms in the products for O and Na: O: | 2 c_1 + c_2 = c_3 Na: | 2 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 = 2 c_3 = 4 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | O_2 + 2 Na_2O ⟶ 4 NaO

+ ⟶ NaO

oxygen + sodium oxide ⟶ NaO

Construct the equilibrium constant, K, expression for: O_2 + Na_2O ⟶ NaO 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: O_2 + 2 Na_2O ⟶ 4 NaO 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 O_2 | 1 | -1 Na_2O | 2 | -2 NaO | 4 | 4 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression O_2 | 1 | -1 | ([O2])^(-1) Na_2O | 2 | -2 | ([Na2O])^(-2) NaO | 4 | 4 | ([NaO])^4 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 = ([O2])^(-1) ([Na2O])^(-2) ([NaO])^4 = ([NaO])^4/([O2] ([Na2O])^2)

Construct the rate of reaction expression for: O_2 + Na_2O ⟶ NaO 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: O_2 + 2 Na_2O ⟶ 4 NaO 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 O_2 | 1 | -1 Na_2O | 2 | -2 NaO | 4 | 4 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 O_2 | 1 | -1 | -(Δ[O2])/(Δt) Na_2O | 2 | -2 | -1/2 (Δ[Na2O])/(Δt) NaO | 4 | 4 | 1/4 (Δ[NaO])/(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[O2])/(Δt) = -1/2 (Δ[Na2O])/(Δt) = 1/4 (Δ[NaO])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| oxygen | sodium oxide | NaO formula | O_2 | Na_2O | NaO name | oxygen | sodium oxide | IUPAC name | molecular oxygen | disodium oxygen(-2) anion |

| oxygen | sodium oxide | NaO molar mass | 31.998 g/mol | 61.979 g/mol | 38.989 g/mol phase | gas (at STP) | | melting point | -218 °C | | boiling point | -183 °C | | density | 0.001429 g/cm^3 (at 0 °C) | 2.27 g/cm^3 | surface tension | 0.01347 N/m | | dynamic viscosity | 2.055×10^-5 Pa s (at 25 °C) | | odor | odorless | |