Na2O + ZnO = Na2ZnO2

Na_2O sodium oxide + ZnO zinc oxide ⟶ Na2ZnO2

Balance the chemical equation algebraically: Na_2O + ZnO ⟶ Na2ZnO2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Na_2O + c_2 ZnO ⟶ c_3 Na2ZnO2 Set the number of atoms in the reactants equal to the number of atoms in the products for Na, O and Zn: Na: | 2 c_1 = 2 c_3 O: | c_1 + c_2 = 2 c_3 Zn: | 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 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | Na_2O + ZnO ⟶ Na2ZnO2

+ ⟶ Na2ZnO2

sodium oxide + zinc oxide ⟶ Na2ZnO2

Construct the equilibrium constant, K, expression for: Na_2O + ZnO ⟶ Na2ZnO2 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: Na_2O + ZnO ⟶ Na2ZnO2 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 Na_2O | 1 | -1 ZnO | 1 | -1 Na2ZnO2 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Na_2O | 1 | -1 | ([Na2O])^(-1) ZnO | 1 | -1 | ([ZnO])^(-1) Na2ZnO2 | 1 | 1 | [Na2ZnO2] 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 = ([Na2O])^(-1) ([ZnO])^(-1) [Na2ZnO2] = ([Na2ZnO2])/([Na2O] [ZnO])

Construct the rate of reaction expression for: Na_2O + ZnO ⟶ Na2ZnO2 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: Na_2O + ZnO ⟶ Na2ZnO2 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 Na_2O | 1 | -1 ZnO | 1 | -1 Na2ZnO2 | 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 Na_2O | 1 | -1 | -(Δ[Na2O])/(Δt) ZnO | 1 | -1 | -(Δ[ZnO])/(Δt) Na2ZnO2 | 1 | 1 | (Δ[Na2ZnO2])/(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[Na2O])/(Δt) = -(Δ[ZnO])/(Δt) = (Δ[Na2ZnO2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| sodium oxide | zinc oxide | Na2ZnO2 formula | Na_2O | ZnO | Na2ZnO2 Hill formula | Na_2O | OZn | Na2O2Zn name | sodium oxide | zinc oxide | IUPAC name | disodium oxygen(-2) anion | oxozinc |

| sodium oxide | zinc oxide | Na2ZnO2 molar mass | 61.979 g/mol | 81.38 g/mol | 143.4 g/mol phase | | solid (at STP) | melting point | | 1975 °C | boiling point | | 2360 °C | density | 2.27 g/cm^3 | 5.6 g/cm^3 | odor | | odorless |