H2SO4 + NaN3 = Na2SO4 + HN3

H_2SO_4 sulfuric acid + NaN_3 sodium azide ⟶ Na_2SO_4 sodium sulfate + HNN congruent N hydrazoic acid

Balance the chemical equation algebraically: H_2SO_4 + NaN_3 ⟶ Na_2SO_4 + HNN congruent N Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_2SO_4 + c_2 NaN_3 ⟶ c_3 Na_2SO_4 + c_4 HNN congruent N Set the number of atoms in the reactants equal to the number of atoms in the products for H, O, S, N and Na: H: | 2 c_1 = c_4 O: | 4 c_1 = 4 c_3 S: | c_1 = c_3 N: | 3 c_2 = 3 c_4 Na: | c_2 = 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 = 1 c_4 = 2 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | H_2SO_4 + 2 NaN_3 ⟶ Na_2SO_4 + 2 HNN congruent N

+ ⟶ +

sulfuric acid + sodium azide ⟶ sodium sulfate + hydrazoic acid

Construct the equilibrium constant, K, expression for: H_2SO_4 + NaN_3 ⟶ Na_2SO_4 + HNN congruent N 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_2SO_4 + 2 NaN_3 ⟶ Na_2SO_4 + 2 HNN congruent N 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_2SO_4 | 1 | -1 NaN_3 | 2 | -2 Na_2SO_4 | 1 | 1 HNN congruent N | 2 | 2 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression H_2SO_4 | 1 | -1 | ([H2SO4])^(-1) NaN_3 | 2 | -2 | ([NaN3])^(-2) Na_2SO_4 | 1 | 1 | [Na2SO4] HNN congruent N | 2 | 2 | ([HNN congruent N])^2 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 = ([H2SO4])^(-1) ([NaN3])^(-2) [Na2SO4] ([HNN congruent N])^2 = ([Na2SO4] ([HNN congruent N])^2)/([H2SO4] ([NaN3])^2)

Construct the rate of reaction expression for: H_2SO_4 + NaN_3 ⟶ Na_2SO_4 + HNN congruent N 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_2SO_4 + 2 NaN_3 ⟶ Na_2SO_4 + 2 HNN congruent N 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_2SO_4 | 1 | -1 NaN_3 | 2 | -2 Na_2SO_4 | 1 | 1 HNN congruent N | 2 | 2 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_2SO_4 | 1 | -1 | -(Δ[H2SO4])/(Δt) NaN_3 | 2 | -2 | -1/2 (Δ[NaN3])/(Δt) Na_2SO_4 | 1 | 1 | (Δ[Na2SO4])/(Δt) HNN congruent N | 2 | 2 | 1/2 (Δ[HNN congruent N])/(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[H2SO4])/(Δt) = -1/2 (Δ[NaN3])/(Δt) = (Δ[Na2SO4])/(Δt) = 1/2 (Δ[HNN congruent N])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| sulfuric acid | sodium azide | sodium sulfate | hydrazoic acid formula | H_2SO_4 | NaN_3 | Na_2SO_4 | HNN congruent N Hill formula | H_2O_4S | N_3Na | Na_2O_4S | HN_3 name | sulfuric acid | sodium azide | sodium sulfate | hydrazoic acid IUPAC name | sulfuric acid | | disodium sulfate | diazonioazanide

| sulfuric acid | sodium azide | sodium sulfate | hydrazoic acid molar mass | 98.07 g/mol | 65.011 g/mol | 142.04 g/mol | 43.029 g/mol phase | liquid (at STP) | solid (at STP) | solid (at STP) | melting point | 10.371 °C | 275 °C | 884 °C | boiling point | 279.6 °C | | 1429 °C | density | 1.8305 g/cm^3 | 1.85 g/cm^3 | 2.68 g/cm^3 | solubility in water | very soluble | | soluble | surface tension | 0.0735 N/m | | | dynamic viscosity | 0.021 Pa s (at 25 °C) | | | odor | odorless | odorless | |