Fe + NiCl2 = FeCl2 + Ni

Fe iron + NiCl_2 nickel(II) chloride ⟶ FeCl_2 iron(II) chloride + Ni nickel

Balance the chemical equation algebraically: Fe + NiCl_2 ⟶ FeCl_2 + Ni Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Fe + c_2 NiCl_2 ⟶ c_3 FeCl_2 + c_4 Ni Set the number of atoms in the reactants equal to the number of atoms in the products for Fe, Cl and Ni: Fe: | c_1 = c_3 Cl: | 2 c_2 = 2 c_3 Ni: | 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 = 1 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | Fe + NiCl_2 ⟶ FeCl_2 + Ni

+ ⟶ +

iron + nickel(II) chloride ⟶ iron(II) chloride + nickel

Construct the equilibrium constant, K, expression for: Fe + NiCl_2 ⟶ FeCl_2 + Ni 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 + NiCl_2 ⟶ FeCl_2 + Ni 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 | 1 | -1 NiCl_2 | 1 | -1 FeCl_2 | 1 | 1 Ni | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Fe | 1 | -1 | ([Fe])^(-1) NiCl_2 | 1 | -1 | ([NiCl2])^(-1) FeCl_2 | 1 | 1 | [FeCl2] Ni | 1 | 1 | [Ni] 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])^(-1) ([NiCl2])^(-1) [FeCl2] [Ni] = ([FeCl2] [Ni])/([Fe] [NiCl2])

Construct the rate of reaction expression for: Fe + NiCl_2 ⟶ FeCl_2 + Ni 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 + NiCl_2 ⟶ FeCl_2 + Ni 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 | 1 | -1 NiCl_2 | 1 | -1 FeCl_2 | 1 | 1 Ni | 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 | 1 | -1 | -(Δ[Fe])/(Δt) NiCl_2 | 1 | -1 | -(Δ[NiCl2])/(Δt) FeCl_2 | 1 | 1 | (Δ[FeCl2])/(Δt) Ni | 1 | 1 | (Δ[Ni])/(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])/(Δt) = -(Δ[NiCl2])/(Δt) = (Δ[FeCl2])/(Δt) = (Δ[Ni])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| iron | nickel(II) chloride | iron(II) chloride | nickel formula | Fe | NiCl_2 | FeCl_2 | Ni Hill formula | Fe | Cl_2Ni | Cl_2Fe | Ni name | iron | nickel(II) chloride | iron(II) chloride | nickel IUPAC name | iron | dichloronickel | dichloroiron | nickel

| iron | nickel(II) chloride | iron(II) chloride | nickel molar mass | 55.845 g/mol | 129.6 g/mol | 126.7 g/mol | 58.6934 g/mol phase | solid (at STP) | | solid (at STP) | solid (at STP) melting point | 1535 °C | | 677 °C | 1453 °C boiling point | 2750 °C | | | 2732 °C density | 7.874 g/cm^3 | 3.55 g/cm^3 | 3.16 g/cm^3 | 8.908 g/cm^3 solubility in water | insoluble | | | insoluble odor | | | | odorless