NaHCO3 = H2O + CO2 + Na2O

NaHCO_3 sodium bicarbonate ⟶ H_2O water + CO_2 carbon dioxide + Na_2O sodium oxide

Balance the chemical equation algebraically: NaHCO_3 ⟶ H_2O + CO_2 + Na_2O Add stoichiometric coefficients, c_i, to the reactants and products: c_1 NaHCO_3 ⟶ c_2 H_2O + c_3 CO_2 + c_4 Na_2O Set the number of atoms in the reactants equal to the number of atoms in the products for C, H, Na and O: C: | c_1 = c_3 H: | c_1 = 2 c_2 Na: | c_1 = 2 c_4 O: | 3 c_1 = c_2 + 2 c_3 + 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_2 = 1 and solve the system of equations for the remaining coefficients: c_1 = 2 c_2 = 1 c_3 = 2 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 NaHCO_3 ⟶ H_2O + 2 CO_2 + Na_2O

⟶ + +

sodium bicarbonate ⟶ water + carbon dioxide + sodium oxide

Construct the equilibrium constant, K, expression for: NaHCO_3 ⟶ H_2O + CO_2 + Na_2O 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: 2 NaHCO_3 ⟶ H_2O + 2 CO_2 + Na_2O 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 NaHCO_3 | 2 | -2 H_2O | 1 | 1 CO_2 | 2 | 2 Na_2O | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression NaHCO_3 | 2 | -2 | ([NaHCO3])^(-2) H_2O | 1 | 1 | [H2O] CO_2 | 2 | 2 | ([CO2])^2 Na_2O | 1 | 1 | [Na2O] 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 = ([NaHCO3])^(-2) [H2O] ([CO2])^2 [Na2O] = ([H2O] ([CO2])^2 [Na2O])/([NaHCO3])^2

Construct the rate of reaction expression for: NaHCO_3 ⟶ H_2O + CO_2 + Na_2O 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: 2 NaHCO_3 ⟶ H_2O + 2 CO_2 + Na_2O 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 NaHCO_3 | 2 | -2 H_2O | 1 | 1 CO_2 | 2 | 2 Na_2O | 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 NaHCO_3 | 2 | -2 | -1/2 (Δ[NaHCO3])/(Δt) H_2O | 1 | 1 | (Δ[H2O])/(Δt) CO_2 | 2 | 2 | 1/2 (Δ[CO2])/(Δt) Na_2O | 1 | 1 | (Δ[Na2O])/(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 = -1/2 (Δ[NaHCO3])/(Δt) = (Δ[H2O])/(Δt) = 1/2 (Δ[CO2])/(Δt) = (Δ[Na2O])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| sodium bicarbonate | water | carbon dioxide | sodium oxide formula | NaHCO_3 | H_2O | CO_2 | Na_2O Hill formula | CHNaO_3 | H_2O | CO_2 | Na_2O name | sodium bicarbonate | water | carbon dioxide | sodium oxide IUPAC name | sodium hydrogen carbonate | water | carbon dioxide | disodium oxygen(-2) anion

| sodium bicarbonate | water | carbon dioxide | sodium oxide molar mass | 84.006 g/mol | 18.015 g/mol | 44.009 g/mol | 61.979 g/mol phase | solid (at STP) | liquid (at STP) | gas (at STP) | melting point | 270 °C | 0 °C | -56.56 °C (at triple point) | boiling point | | 99.9839 °C | -78.5 °C (at sublimation point) | density | 2.16 g/cm^3 | 1 g/cm^3 | 0.00184212 g/cm^3 (at 20 °C) | 2.27 g/cm^3 solubility in water | soluble | | | surface tension | | 0.0728 N/m | | dynamic viscosity | | 8.9×10^-4 Pa s (at 25 °C) | 1.491×10^-5 Pa s (at 25 °C) | odor | odorless | odorless | odorless |