(NH4)2SO4 = NH3 + NH4HSO4

(NH_4)_2SO_4 ammonium sulfate ⟶ NH_3 ammonia + (NH_4)HSO_4 ammonium bisulfate

Balance the chemical equation algebraically: (NH_4)_2SO_4 ⟶ NH_3 + (NH_4)HSO_4 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 (NH_4)_2SO_4 ⟶ c_2 NH_3 + c_3 (NH_4)HSO_4 Set the number of atoms in the reactants equal to the number of atoms in the products for H, N, O and S: H: | 8 c_1 = 3 c_2 + 5 c_3 N: | 2 c_1 = c_2 + c_3 O: | 4 c_1 = 4 c_3 S: | c_1 = 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 = 1 c_3 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | (NH_4)_2SO_4 ⟶ NH_3 + (NH_4)HSO_4

⟶ +

ammonium sulfate ⟶ ammonia + ammonium bisulfate

| ammonium sulfate | ammonia | ammonium bisulfate molecular enthalpy | -1181 kJ/mol | -45.9 kJ/mol | -1027 kJ/mol total enthalpy | -1181 kJ/mol | -45.9 kJ/mol | -1027 kJ/mol | H_initial = -1181 kJ/mol | H_final = -1073 kJ/mol | ΔH_rxn^0 | -1073 kJ/mol - -1181 kJ/mol = 108 kJ/mol (endothermic) | |

Construct the equilibrium constant, K, expression for: (NH_4)_2SO_4 ⟶ NH_3 + (NH_4)HSO_4 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_4)_2SO_4 ⟶ NH_3 + (NH_4)HSO_4 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_4)_2SO_4 | 1 | -1 NH_3 | 1 | 1 (NH_4)HSO_4 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression (NH_4)_2SO_4 | 1 | -1 | ([(NH4)2SO4])^(-1) NH_3 | 1 | 1 | [NH3] (NH_4)HSO_4 | 1 | 1 | [(NH4)HSO4] 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 = ([(NH4)2SO4])^(-1) [NH3] [(NH4)HSO4] = ([NH3] [(NH4)HSO4])/([(NH4)2SO4])

Construct the rate of reaction expression for: (NH_4)_2SO_4 ⟶ NH_3 + (NH_4)HSO_4 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_4)_2SO_4 ⟶ NH_3 + (NH_4)HSO_4 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_4)_2SO_4 | 1 | -1 NH_3 | 1 | 1 (NH_4)HSO_4 | 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_4)_2SO_4 | 1 | -1 | -(Δ[(NH4)2SO4])/(Δt) NH_3 | 1 | 1 | (Δ[NH3])/(Δt) (NH_4)HSO_4 | 1 | 1 | (Δ[(NH4)HSO4])/(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[(NH4)2SO4])/(Δt) = (Δ[NH3])/(Δt) = (Δ[(NH4)HSO4])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| ammonium sulfate | ammonia | ammonium bisulfate formula | (NH_4)_2SO_4 | NH_3 | (NH_4)HSO_4 Hill formula | H_8N_2O_4S | H_3N | H_5NO_4S name | ammonium sulfate | ammonia | ammonium bisulfate IUPAC name | | ammonia | ammonium hydrogen sulfate

| ammonium sulfate | ammonia | ammonium bisulfate molar mass | 132.1 g/mol | 17.031 g/mol | 115.1 g/mol phase | solid (at STP) | gas (at STP) | solid (at STP) melting point | 280 °C | -77.73 °C | 147 °C boiling point | | -33.33 °C | 350 °C density | 1.77 g/cm^3 | 6.96×10^-4 g/cm^3 (at 25 °C) | 1.79 g/cm^3 solubility in water | | | soluble surface tension | | 0.0234 N/m | dynamic viscosity | | 1.009×10^-5 Pa s (at 25 °C) | odor | odorless | |