NH4NO3 = HNO3 + NH3

NH_4NO_3 ammonium nitrate ⟶ HNO_3 nitric acid + NH_3 ammonia

Balance the chemical equation algebraically: NH_4NO_3 ⟶ HNO_3 + NH_3 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 NH_4NO_3 ⟶ c_2 HNO_3 + c_3 NH_3 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 = c_2 + 3 c_3 N: | 2 c_1 = c_2 + c_3 O: | 3 c_1 = 3 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: | | NH_4NO_3 ⟶ HNO_3 + NH_3

⟶ +

ammonium nitrate ⟶ nitric acid + ammonia

| ammonium nitrate | nitric acid | ammonia molecular free energy | -183.9 kJ/mol | -80.7 kJ/mol | -16.4 kJ/mol total free energy | -183.9 kJ/mol | -80.7 kJ/mol | -16.4 kJ/mol | G_initial = -183.9 kJ/mol | G_final = -97.1 kJ/mol | ΔG_rxn^0 | -97.1 kJ/mol - -183.9 kJ/mol = 86.8 kJ/mol (endergonic) | |

Construct the equilibrium constant, K, expression for: NH_4NO_3 ⟶ HNO_3 + NH_3 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: NH_4NO_3 ⟶ HNO_3 + NH_3 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 NH_4NO_3 | 1 | -1 HNO_3 | 1 | 1 NH_3 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression NH_4NO_3 | 1 | -1 | ([NH4NO3])^(-1) HNO_3 | 1 | 1 | [HNO3] NH_3 | 1 | 1 | [NH3] 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 = ([NH4NO3])^(-1) [HNO3] [NH3] = ([HNO3] [NH3])/([NH4NO3])

Construct the rate of reaction expression for: NH_4NO_3 ⟶ HNO_3 + NH_3 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: NH_4NO_3 ⟶ HNO_3 + NH_3 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 NH_4NO_3 | 1 | -1 HNO_3 | 1 | 1 NH_3 | 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 NH_4NO_3 | 1 | -1 | -(Δ[NH4NO3])/(Δt) HNO_3 | 1 | 1 | (Δ[HNO3])/(Δt) NH_3 | 1 | 1 | (Δ[NH3])/(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[NH4NO3])/(Δt) = (Δ[HNO3])/(Δt) = (Δ[NH3])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| ammonium nitrate | nitric acid | ammonia formula | NH_4NO_3 | HNO_3 | NH_3 Hill formula | H_4N_2O_3 | HNO_3 | H_3N name | ammonium nitrate | nitric acid | ammonia

| ammonium nitrate | nitric acid | ammonia molar mass | 80.04 g/mol | 63.012 g/mol | 17.031 g/mol phase | solid (at STP) | liquid (at STP) | gas (at STP) melting point | 169 °C | -41.6 °C | -77.73 °C boiling point | 210 °C | 83 °C | -33.33 °C density | 1.73 g/cm^3 | 1.5129 g/cm^3 | 6.96×10^-4 g/cm^3 (at 25 °C) solubility in water | | miscible | surface tension | | | 0.0234 N/m dynamic viscosity | | 7.6×10^-4 Pa s (at 25 °C) | 1.009×10^-5 Pa s (at 25 °C) odor | odorless | |