Cu + HgSO4 = Hg + Cu(SO4)2

Cu copper + HgSO_4 mercuric sulfate ⟶ Hg mercury + Cu(SO4)2

Balance the chemical equation algebraically: Cu + HgSO_4 ⟶ Hg + Cu(SO4)2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Cu + c_2 HgSO_4 ⟶ c_3 Hg + c_4 Cu(SO4)2 Set the number of atoms in the reactants equal to the number of atoms in the products for Cu, Hg, O and S: Cu: | c_1 = c_4 Hg: | c_2 = c_3 O: | 4 c_2 = 8 c_4 S: | c_2 = 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 = 2 c_3 = 2 c_4 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | Cu + 2 HgSO_4 ⟶ 2 Hg + Cu(SO4)2

+ ⟶ + Cu(SO4)2

copper + mercuric sulfate ⟶ mercury + Cu(SO4)2

Construct the equilibrium constant, K, expression for: Cu + HgSO_4 ⟶ Hg + Cu(SO4)2 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 + 2 HgSO_4 ⟶ 2 Hg + Cu(SO4)2 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 HgSO_4 | 2 | -2 Hg | 2 | 2 Cu(SO4)2 | 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) HgSO_4 | 2 | -2 | ([HgSO4])^(-2) Hg | 2 | 2 | ([Hg])^2 Cu(SO4)2 | 1 | 1 | [Cu(SO4)2] 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) ([HgSO4])^(-2) ([Hg])^2 [Cu(SO4)2] = (([Hg])^2 [Cu(SO4)2])/([Cu] ([HgSO4])^2)

Construct the rate of reaction expression for: Cu + HgSO_4 ⟶ Hg + Cu(SO4)2 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 + 2 HgSO_4 ⟶ 2 Hg + Cu(SO4)2 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 HgSO_4 | 2 | -2 Hg | 2 | 2 Cu(SO4)2 | 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) HgSO_4 | 2 | -2 | -1/2 (Δ[HgSO4])/(Δt) Hg | 2 | 2 | 1/2 (Δ[Hg])/(Δt) Cu(SO4)2 | 1 | 1 | (Δ[Cu(SO4)2])/(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) = -1/2 (Δ[HgSO4])/(Δt) = 1/2 (Δ[Hg])/(Δt) = (Δ[Cu(SO4)2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| copper | mercuric sulfate | mercury | Cu(SO4)2 formula | Cu | HgSO_4 | Hg | Cu(SO4)2 Hill formula | Cu | HgO_4S | Hg | CuO8S2 name | copper | mercuric sulfate | mercury | IUPAC name | copper | mercury(+2) cation sulfate | mercury |

| copper | mercuric sulfate | mercury | Cu(SO4)2 molar mass | 63.546 g/mol | 296.65 g/mol | 200.592 g/mol | 255.7 g/mol phase | solid (at STP) | solid (at STP) | liquid (at STP) | melting point | 1083 °C | 850 °C | -38.87 °C | boiling point | 2567 °C | | 356.6 °C | density | 8.96 g/cm^3 | 5.995 g/cm^3 | 13.534 g/cm^3 | solubility in water | insoluble | decomposes | slightly soluble | surface tension | | | 0.47 N/m | dynamic viscosity | | | 0.001526 Pa s (at 25 °C) | odor | odorless | | odorless |