Pb(OH)2 = H2O + PbO

Pb(OH)_2 lead(II) hydroxide ⟶ H_2O water + PbO lead monoxide

Balance the chemical equation algebraically: Pb(OH)_2 ⟶ H_2O + PbO Add stoichiometric coefficients, c_i, to the reactants and products: c_1 Pb(OH)_2 ⟶ c_2 H_2O + c_3 PbO Set the number of atoms in the reactants equal to the number of atoms in the products for H, O and Pb: H: | 2 c_1 = 2 c_2 O: | 2 c_1 = c_2 + c_3 Pb: | c_1 = c_3 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 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | Pb(OH)_2 ⟶ H_2O + PbO

⟶ +

lead(II) hydroxide ⟶ water + lead monoxide

Construct the equilibrium constant, K, expression for: Pb(OH)_2 ⟶ H_2O + PbO 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: Pb(OH)_2 ⟶ H_2O + PbO 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 Pb(OH)_2 | 1 | -1 H_2O | 1 | 1 PbO | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression Pb(OH)_2 | 1 | -1 | ([Pb(OH)2])^(-1) H_2O | 1 | 1 | [H2O] PbO | 1 | 1 | [PbO] 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 = ([Pb(OH)2])^(-1) [H2O] [PbO] = ([H2O] [PbO])/([Pb(OH)2])

Construct the rate of reaction expression for: Pb(OH)_2 ⟶ H_2O + PbO 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: Pb(OH)_2 ⟶ H_2O + PbO 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 Pb(OH)_2 | 1 | -1 H_2O | 1 | 1 PbO | 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 Pb(OH)_2 | 1 | -1 | -(Δ[Pb(OH)2])/(Δt) H_2O | 1 | 1 | (Δ[H2O])/(Δt) PbO | 1 | 1 | (Δ[PbO])/(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[Pb(OH)2])/(Δt) = (Δ[H2O])/(Δt) = (Δ[PbO])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| lead(II) hydroxide | water | lead monoxide formula | Pb(OH)_2 | H_2O | PbO Hill formula | H_2O_2Pb | H_2O | OPb name | lead(II) hydroxide | water | lead monoxide IUPAC name | plumbous dihydroxide | water |

| lead(II) hydroxide | water | lead monoxide molar mass | 241.2 g/mol | 18.015 g/mol | 223.2 g/mol phase | | liquid (at STP) | solid (at STP) melting point | | 0 °C | 886 °C boiling point | | 99.9839 °C | 1470 °C density | | 1 g/cm^3 | 9.5 g/cm^3 solubility in water | | | insoluble surface tension | | 0.0728 N/m | dynamic viscosity | | 8.9×10^-4 Pa s (at 25 °C) | 1.45×10^-4 Pa s (at 1000 °C) odor | | odorless |