Cu + HgCl2 = CuCl2 + Hg

Cu copper + HgCl_2 mercuric chloride ⟶ CuCl_2 copper(II) chloride + Hg mercury

Balance the chemical equation algebraically: Cu + HgCl_2 ⟶ CuCl_2 + Hg Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Cu + c_2 HgCl_2 ⟶ c_3 CuCl_2 + c_4 Hg Set the number of atoms in the reactants equal to the number of atoms in the products for Cu, Cl and Hg: Cu: | c_1 = c_3 Cl: | 2 c_2 = 2 c_3 Hg: | 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: | | Cu + HgCl_2 ⟶ CuCl_2 + Hg

+ ⟶ +

copper + mercuric chloride ⟶ copper(II) chloride + mercury

| copper | mercuric chloride | copper(II) chloride | mercury molecular enthalpy | 0 kJ/mol | -224.3 kJ/mol | -220.1 kJ/mol | 0 kJ/mol total enthalpy | 0 kJ/mol | -224.3 kJ/mol | -220.1 kJ/mol | 0 kJ/mol | H_initial = -224.3 kJ/mol | | H_final = -220.1 kJ/mol | ΔH_rxn^0 | -220.1 kJ/mol - -224.3 kJ/mol = 4.2 kJ/mol (endothermic) | | |

Construct the equilibrium constant, K, expression for: Cu + HgCl_2 ⟶ CuCl_2 + Hg 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: Cu + HgCl_2 ⟶ CuCl_2 + Hg 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 Cu | 1 | -1 HgCl_2 | 1 | -1 CuCl_2 | 1 | 1 Hg | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Cu | 1 | -1 | ([Cu])^(-1) HgCl_2 | 1 | -1 | ([HgCl2])^(-1) CuCl_2 | 1 | 1 | [CuCl2] Hg | 1 | 1 | [Hg] 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 = ([Cu])^(-1) ([HgCl2])^(-1) [CuCl2] [Hg] = ([CuCl2] [Hg])/([Cu] [HgCl2])

Construct the rate of reaction expression for: Cu + HgCl_2 ⟶ CuCl_2 + Hg 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: Cu + HgCl_2 ⟶ CuCl_2 + Hg 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 Cu | 1 | -1 HgCl_2 | 1 | -1 CuCl_2 | 1 | 1 Hg | 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 Cu | 1 | -1 | -(Δ[Cu])/(Δt) HgCl_2 | 1 | -1 | -(Δ[HgCl2])/(Δt) CuCl_2 | 1 | 1 | (Δ[CuCl2])/(Δt) Hg | 1 | 1 | (Δ[Hg])/(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[Cu])/(Δt) = -(Δ[HgCl2])/(Δt) = (Δ[CuCl2])/(Δt) = (Δ[Hg])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| copper | mercuric chloride | copper(II) chloride | mercury formula | Cu | HgCl_2 | CuCl_2 | Hg Hill formula | Cu | Cl_2Hg | Cl_2Cu | Hg name | copper | mercuric chloride | copper(II) chloride | mercury IUPAC name | copper | dichloromercury | dichlorocopper | mercury

| copper | mercuric chloride | copper(II) chloride | mercury molar mass | 63.546 g/mol | 271.49 g/mol | 134.4 g/mol | 200.592 g/mol phase | solid (at STP) | solid (at STP) | solid (at STP) | liquid (at STP) melting point | 1083 °C | 277 °C | 620 °C | -38.87 °C boiling point | 2567 °C | 302 °C | | 356.6 °C density | 8.96 g/cm^3 | 5.44 g/cm^3 | 3.386 g/cm^3 | 13.534 g/cm^3 solubility in water | insoluble | | | slightly soluble surface tension | | | | 0.47 N/m dynamic viscosity | | | | 0.001526 Pa s (at 25 °C) odor | odorless | odorless | | odorless