(NH4)NO2 = H2O + N2

H_4N_2O_2 ammonium nitrite ⟶ H_2O water + N_2 nitrogen

Balance the chemical equation algebraically: H_4N_2O_2 ⟶ H_2O + N_2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_4N_2O_2 ⟶ c_2 H_2O + c_3 N_2 Set the number of atoms in the reactants equal to the number of atoms in the products for H, N and O: H: | 4 c_1 = 2 c_2 N: | 2 c_1 = 2 c_3 O: | 2 c_1 = 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 = 2 c_3 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | H_4N_2O_2 ⟶ 2 H_2O + N_2

⟶ +

ammonium nitrite ⟶ water + nitrogen

Construct the equilibrium constant, K, expression for: H_4N_2O_2 ⟶ H_2O + N_2 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: H_4N_2O_2 ⟶ 2 H_2O + N_2 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 H_4N_2O_2 | 1 | -1 H_2O | 2 | 2 N_2 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression H_4N_2O_2 | 1 | -1 | ([H4N2O2])^(-1) H_2O | 2 | 2 | ([H2O])^2 N_2 | 1 | 1 | [N2] 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 = ([H4N2O2])^(-1) ([H2O])^2 [N2] = (([H2O])^2 [N2])/([H4N2O2])

Construct the rate of reaction expression for: H_4N_2O_2 ⟶ H_2O + N_2 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: H_4N_2O_2 ⟶ 2 H_2O + N_2 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 H_4N_2O_2 | 1 | -1 H_2O | 2 | 2 N_2 | 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 H_4N_2O_2 | 1 | -1 | -(Δ[H4N2O2])/(Δt) H_2O | 2 | 2 | 1/2 (Δ[H2O])/(Δt) N_2 | 1 | 1 | (Δ[N2])/(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[H4N2O2])/(Δt) = 1/2 (Δ[H2O])/(Δt) = (Δ[N2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| ammonium nitrite | water | nitrogen formula | H_4N_2O_2 | H_2O | N_2 name | ammonium nitrite | water | nitrogen IUPAC name | azanium nitrite | water | molecular nitrogen

| ammonium nitrite | water | nitrogen molar mass | 64.04 g/mol | 18.015 g/mol | 28.014 g/mol phase | | liquid (at STP) | gas (at STP) melting point | | 0 °C | -210 °C boiling point | | 99.9839 °C | -195.79 °C density | | 1 g/cm^3 | 0.001251 g/cm^3 (at 0 °C) solubility in water | soluble | | insoluble surface tension | | 0.0728 N/m | 0.0066 N/m dynamic viscosity | | 8.9×10^-4 Pa s (at 25 °C) | 1.78×10^-5 Pa s (at 25 °C) odor | | odorless | odorless