Zn + Hg(NO3)2 = Hg + Zn(NO3)2

Zn zinc + Hg(NO_3)_2 mercury(II) nitrate ⟶ Hg mercury + Zn(NO3)2

Balance the chemical equation algebraically: Zn + Hg(NO_3)_2 ⟶ Hg + Zn(NO3)2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Zn + c_2 Hg(NO_3)_2 ⟶ c_3 Hg + c_4 Zn(NO3)2 Set the number of atoms in the reactants equal to the number of atoms in the products for Zn, Hg, N and O: Zn: | c_1 = c_4 Hg: | c_2 = c_3 N: | 2 c_2 = 2 c_4 O: | 6 c_2 = 6 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: | | Zn + Hg(NO_3)_2 ⟶ Hg + Zn(NO3)2

+ ⟶ + Zn(NO3)2

zinc + mercury(II) nitrate ⟶ mercury + Zn(NO3)2

Construct the equilibrium constant, K, expression for: Zn + Hg(NO_3)_2 ⟶ Hg + Zn(NO3)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: Zn + Hg(NO_3)_2 ⟶ Hg + Zn(NO3)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 Zn | 1 | -1 Hg(NO_3)_2 | 1 | -1 Hg | 1 | 1 Zn(NO3)2 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Zn | 1 | -1 | ([Zn])^(-1) Hg(NO_3)_2 | 1 | -1 | ([Hg(NO3)2])^(-1) Hg | 1 | 1 | [Hg] Zn(NO3)2 | 1 | 1 | [Zn(NO3)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 = ([Zn])^(-1) ([Hg(NO3)2])^(-1) [Hg] [Zn(NO3)2] = ([Hg] [Zn(NO3)2])/([Zn] [Hg(NO3)2])

Construct the rate of reaction expression for: Zn + Hg(NO_3)_2 ⟶ Hg + Zn(NO3)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: Zn + Hg(NO_3)_2 ⟶ Hg + Zn(NO3)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 Zn | 1 | -1 Hg(NO_3)_2 | 1 | -1 Hg | 1 | 1 Zn(NO3)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 Zn | 1 | -1 | -(Δ[Zn])/(Δt) Hg(NO_3)_2 | 1 | -1 | -(Δ[Hg(NO3)2])/(Δt) Hg | 1 | 1 | (Δ[Hg])/(Δt) Zn(NO3)2 | 1 | 1 | (Δ[Zn(NO3)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[Zn])/(Δt) = -(Δ[Hg(NO3)2])/(Δt) = (Δ[Hg])/(Δt) = (Δ[Zn(NO3)2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| zinc | mercury(II) nitrate | mercury | Zn(NO3)2 formula | Zn | Hg(NO_3)_2 | Hg | Zn(NO3)2 Hill formula | Zn | HgN_2O_6 | Hg | N2O6Zn name | zinc | mercury(II) nitrate | mercury | IUPAC name | zinc | mercury(+2) cation dinitrate | mercury |

| zinc | mercury(II) nitrate | mercury | Zn(NO3)2 molar mass | 65.38 g/mol | 324.6 g/mol | 200.592 g/mol | 189.4 g/mol phase | solid (at STP) | solid (at STP) | liquid (at STP) | melting point | 420 °C | 79 °C | -38.87 °C | boiling point | 907 °C | | 356.6 °C | density | 7.14 g/cm^3 | 4.3 g/cm^3 | 13.534 g/cm^3 | solubility in water | insoluble | soluble | slightly soluble | surface tension | | | 0.47 N/m | dynamic viscosity | | | 0.001526 Pa s (at 25 °C) | odor | odorless | | odorless |