NH3HCl = NH4Cl

NH_4Cl ammonium chloride ⟶ NH_4Cl ammonium chloride

Balance the chemical equation algebraically: NH_4Cl ⟶ NH_4Cl Add stoichiometric coefficients, c_i, to the reactants and products: c_1 NH_4Cl ⟶ c_2 NH_4Cl Set the number of atoms in the reactants equal to the number of atoms in the products for Cl, H and N: Cl: | c_1 = c_2 H: | 4 c_1 = 4 c_2 N: | 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 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | NH_4Cl ⟶ NH_4Cl

⟶

ammonium chloride ⟶ ammonium chloride

| ammonium chloride | ammonium chloride molecular enthalpy | -314.4 kJ/mol | -314.4 kJ/mol total enthalpy | -314.4 kJ/mol | -314.4 kJ/mol | H_initial = -314.4 kJ/mol | H_final = -314.4 kJ/mol ΔH_rxn^0 | -314.4 kJ/mol - -314.4 kJ/mol = 0 kJ/mol (equilibrium) |

| ammonium chloride | ammonium chloride molecular free energy | -202.9 kJ/mol | -202.9 kJ/mol total free energy | -202.9 kJ/mol | -202.9 kJ/mol | G_initial = -202.9 kJ/mol | G_final = -202.9 kJ/mol ΔG_rxn^0 | -202.9 kJ/mol - -202.9 kJ/mol = 0 kJ/mol (equilibrium) |

| ammonium chloride | ammonium chloride molecular entropy | 96 J/(mol K) | 96 J/(mol K) total entropy | 96 J/(mol K) | 96 J/(mol K) | S_initial = 96 J/(mol K) | S_final = 96 J/(mol K) ΔS_rxn^0 | 96 J/(mol K) - 96 J/(mol K) = 0 J/(mol K) (equilibrium) |

Construct the equilibrium constant, K, expression for: NH_4Cl ⟶ NH_4Cl 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_4Cl ⟶ NH_4Cl 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_4Cl | 1 | -1 NH_4Cl | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression NH_4Cl | 1 | -1 | ([NH4Cl])^(-1) NH_4Cl | 1 | 1 | [NH4Cl] 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 = ([NH4Cl])^(-1) [NH4Cl] = ([NH4Cl])/([NH4Cl])

Construct the rate of reaction expression for: NH_4Cl ⟶ NH_4Cl 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_4Cl ⟶ NH_4Cl 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_4Cl | 1 | -1 NH_4Cl | 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_4Cl | 1 | -1 | -(Δ[NH4Cl])/(Δt) NH_4Cl | 1 | 1 | (Δ[NH4Cl])/(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[NH4Cl])/(Δt) = (Δ[NH4Cl])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| ammonium chloride | ammonium chloride formula | NH_4Cl | NH_4Cl Hill formula | ClH_4N | ClH_4N name | ammonium chloride | ammonium chloride

| ammonium chloride | ammonium chloride molar mass | 53.49 g/mol | 53.49 g/mol phase | solid (at STP) | solid (at STP) melting point | 340 °C | 340 °C density | 1.5256 g/cm^3 | 1.5256 g/cm^3 solubility in water | soluble | soluble