NaNO2 = NO2 + Na

NaNO_2 (sodium nitrite) ⟶ NO_2 (nitrogen dioxide) + Na (sodium)

Balance the chemical equation algebraically: NaNO_2 ⟶ NO_2 + Na Add stoichiometric coefficients, c_i, to the reactants and products: c_1 NaNO_2 ⟶ c_2 NO_2 + c_3 Na Set the number of atoms in the reactants equal to the number of atoms in the products for N, Na and O: N: | c_1 = c_2 Na: | c_1 = c_3 O: | 2 c_1 = 2 c_2 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: | | NaNO_2 ⟶ NO_2 + Na

⟶ +

sodium nitrite ⟶ nitrogen dioxide + sodium

| sodium nitrite | nitrogen dioxide | sodium molecular enthalpy | -359 kJ/mol | 33.2 kJ/mol | 0 kJ/mol total enthalpy | -359 kJ/mol | 33.2 kJ/mol | 0 kJ/mol | H_initial = -359 kJ/mol | H_final = 33.2 kJ/mol | ΔH_rxn^0 | 33.2 kJ/mol - -359 kJ/mol = 392.2 kJ/mol (endothermic) | |

Construct the equilibrium constant, K, expression for: NaNO_2 ⟶ NO_2 + Na 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: NaNO_2 ⟶ NO_2 + Na 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 NaNO_2 | 1 | -1 NO_2 | 1 | 1 Na | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression NaNO_2 | 1 | -1 | ([NaNO2])^(-1) NO_2 | 1 | 1 | [NO2] Na | 1 | 1 | [Na] 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 = ([NaNO2])^(-1) [NO2] [Na] = ([NO2] [Na])/([NaNO2])

Construct the rate of reaction expression for: NaNO_2 ⟶ NO_2 + Na 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: NaNO_2 ⟶ NO_2 + Na 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 NaNO_2 | 1 | -1 NO_2 | 1 | 1 Na | 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 NaNO_2 | 1 | -1 | -(Δ[NaNO2])/(Δt) NO_2 | 1 | 1 | (Δ[NO2])/(Δt) Na | 1 | 1 | (Δ[Na])/(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[NaNO2])/(Δt) = (Δ[NO2])/(Δt) = (Δ[Na])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| sodium nitrite | nitrogen dioxide | sodium formula | NaNO_2 | NO_2 | Na Hill formula | NNaO_2 | NO_2 | Na name | sodium nitrite | nitrogen dioxide | sodium IUPAC name | sodium nitrite | Nitrogen dioxide | sodium

| sodium nitrite | nitrogen dioxide | sodium molar mass | 68.995 g/mol | 46.005 g/mol | 22.98976928 g/mol phase | solid (at STP) | gas (at STP) | solid (at STP) melting point | 271 °C | -11 °C | 97.8 °C boiling point | | 21 °C | 883 °C density | 2.168 g/cm^3 | 0.00188 g/cm^3 (at 25 °C) | 0.968 g/cm^3 solubility in water | | reacts | decomposes dynamic viscosity | | 4.02×10^-4 Pa s (at 25 °C) | 1.413×10^-5 Pa s (at 527 °C)