PtCl4 = Cl2 + Pt

PtCl_4 platinum(IV) chloride ⟶ Cl_2 chlorine + Pt platinum

Balance the chemical equation algebraically: PtCl_4 ⟶ Cl_2 + Pt Add stoichiometric coefficients, c_i, to the reactants and products: c_1 PtCl_4 ⟶ c_2 Cl_2 + c_3 Pt Set the number of atoms in the reactants equal to the number of atoms in the products for Cl and Pt: Cl: | 4 c_1 = 2 c_2 Pt: | 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 = 2 c_3 = 1 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | PtCl_4 ⟶ 2 Cl_2 + Pt

⟶ +

platinum(IV) chloride ⟶ chlorine + platinum

| platinum(IV) chloride | chlorine | platinum molecular enthalpy | -231.8 kJ/mol | 0 kJ/mol | 0 kJ/mol total enthalpy | -231.8 kJ/mol | 0 kJ/mol | 0 kJ/mol | H_initial = -231.8 kJ/mol | H_final = 0 kJ/mol | ΔH_rxn^0 | 0 kJ/mol - -231.8 kJ/mol = 231.8 kJ/mol (endothermic) | |

Construct the equilibrium constant, K, expression for: PtCl_4 ⟶ Cl_2 + Pt 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: PtCl_4 ⟶ 2 Cl_2 + Pt 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 PtCl_4 | 1 | -1 Cl_2 | 2 | 2 Pt | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression PtCl_4 | 1 | -1 | ([PtCl4])^(-1) Cl_2 | 2 | 2 | ([Cl2])^2 Pt | 1 | 1 | [Pt] 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 = ([PtCl4])^(-1) ([Cl2])^2 [Pt] = (([Cl2])^2 [Pt])/([PtCl4])

Construct the rate of reaction expression for: PtCl_4 ⟶ Cl_2 + Pt 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: PtCl_4 ⟶ 2 Cl_2 + Pt 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 PtCl_4 | 1 | -1 Cl_2 | 2 | 2 Pt | 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 PtCl_4 | 1 | -1 | -(Δ[PtCl4])/(Δt) Cl_2 | 2 | 2 | 1/2 (Δ[Cl2])/(Δt) Pt | 1 | 1 | (Δ[Pt])/(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[PtCl4])/(Δt) = 1/2 (Δ[Cl2])/(Δt) = (Δ[Pt])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| platinum(IV) chloride | chlorine | platinum formula | PtCl_4 | Cl_2 | Pt Hill formula | Cl_4Pt | Cl_2 | Pt name | platinum(IV) chloride | chlorine | platinum IUPAC name | tetrachloroplatinum | molecular chlorine | platinum

| platinum(IV) chloride | chlorine | platinum molar mass | 336.9 g/mol | 70.9 g/mol | 195.084 g/mol phase | solid (at STP) | gas (at STP) | solid (at STP) melting point | 370 °C | -101 °C | 1772 °C boiling point | | -34 °C | 3827 °C density | 4.303 g/cm^3 | 0.003214 g/cm^3 (at 0 °C) | 21.45 g/cm^3 solubility in water | | | insoluble