Fe(NO3)3 + K3PO4 = KNO3 + FePO4

Fe(NO_3)_3 ferric nitrate + K3PO4 ⟶ KNO_3 potassium nitrate + FePO_4 iron(III) phosphate

Balance the chemical equation algebraically: Fe(NO_3)_3 + K3PO4 ⟶ KNO_3 + FePO_4 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Fe(NO_3)_3 + c_2 K3PO4 ⟶ c_3 KNO_3 + c_4 FePO_4 Set the number of atoms in the reactants equal to the number of atoms in the products for Fe, N, O, K and P: Fe: | c_1 = c_4 N: | 3 c_1 = c_3 O: | 9 c_1 + 4 c_2 = 3 c_3 + 4 c_4 K: | 3 c_2 = c_3 P: | c_2 = c_4 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 = 3 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | Fe(NO_3)_3 + K3PO4 ⟶ 3 KNO_3 + FePO_4

+ K3PO4 ⟶ +

ferric nitrate + K3PO4 ⟶ potassium nitrate + iron(III) phosphate

Construct the equilibrium constant, K, expression for: Fe(NO_3)_3 + K3PO4 ⟶ KNO_3 + FePO_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: Fe(NO_3)_3 + K3PO4 ⟶ 3 KNO_3 + FePO_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 Fe(NO_3)_3 | 1 | -1 K3PO4 | 1 | -1 KNO_3 | 3 | 3 FePO_4 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Fe(NO_3)_3 | 1 | -1 | ([Fe(NO3)3])^(-1) K3PO4 | 1 | -1 | ([K3PO4])^(-1) KNO_3 | 3 | 3 | ([KNO3])^3 FePO_4 | 1 | 1 | [FePO4] 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 = ([Fe(NO3)3])^(-1) ([K3PO4])^(-1) ([KNO3])^3 [FePO4] = (([KNO3])^3 [FePO4])/([Fe(NO3)3] [K3PO4])

Construct the rate of reaction expression for: Fe(NO_3)_3 + K3PO4 ⟶ KNO_3 + FePO_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: Fe(NO_3)_3 + K3PO4 ⟶ 3 KNO_3 + FePO_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 Fe(NO_3)_3 | 1 | -1 K3PO4 | 1 | -1 KNO_3 | 3 | 3 FePO_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 Fe(NO_3)_3 | 1 | -1 | -(Δ[Fe(NO3)3])/(Δt) K3PO4 | 1 | -1 | -(Δ[K3PO4])/(Δt) KNO_3 | 3 | 3 | 1/3 (Δ[KNO3])/(Δt) FePO_4 | 1 | 1 | (Δ[FePO4])/(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[Fe(NO3)3])/(Δt) = -(Δ[K3PO4])/(Δt) = 1/3 (Δ[KNO3])/(Δt) = (Δ[FePO4])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| ferric nitrate | K3PO4 | potassium nitrate | iron(III) phosphate formula | Fe(NO_3)_3 | K3PO4 | KNO_3 | FePO_4 Hill formula | FeN_3O_9 | K3O4P | KNO_3 | FeO_4P name | ferric nitrate | | potassium nitrate | iron(III) phosphate IUPAC name | iron(+3) cation trinitrate | | potassium nitrate | iron(+3) cation phosphate

| ferric nitrate | K3PO4 | potassium nitrate | iron(III) phosphate molar mass | 241.86 g/mol | 212.26 g/mol | 101.1 g/mol | 150.81 g/mol phase | solid (at STP) | | solid (at STP) | melting point | 35 °C | | 334 °C | density | 1.7 g/cm^3 | | | 2.87 g/cm^3 solubility in water | very soluble | | soluble | odor | | | odorless |