O2 + Cl2 = Cl2O2

O_2 oxygen + Cl_2 chlorine ⟶ Cl2O2

Balance the chemical equation algebraically: O_2 + Cl_2 ⟶ Cl2O2 Add stoichiometric coefficients, c_i, to the reactants and products: c_1 O_2 + c_2 Cl_2 ⟶ c_3 Cl2O2 Set the number of atoms in the reactants equal to the number of atoms in the products for O and Cl: O: | 2 c_1 = 2 c_3 Cl: | 2 c_2 = 2 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: | | O_2 + Cl_2 ⟶ Cl2O2

+ ⟶ Cl2O2

oxygen + chlorine ⟶ Cl2O2

Construct the equilibrium constant, K, expression for: O_2 + Cl_2 ⟶ Cl2O2 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: O_2 + Cl_2 ⟶ Cl2O2 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 O_2 | 1 | -1 Cl_2 | 1 | -1 Cl2O2 | 1 | 1 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression O_2 | 1 | -1 | ([O2])^(-1) Cl_2 | 1 | -1 | ([Cl2])^(-1) Cl2O2 | 1 | 1 | [Cl2O2] 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 = ([O2])^(-1) ([Cl2])^(-1) [Cl2O2] = ([Cl2O2])/([O2] [Cl2])

Construct the rate of reaction expression for: O_2 + Cl_2 ⟶ Cl2O2 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: O_2 + Cl_2 ⟶ Cl2O2 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 O_2 | 1 | -1 Cl_2 | 1 | -1 Cl2O2 | 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 O_2 | 1 | -1 | -(Δ[O2])/(Δt) Cl_2 | 1 | -1 | -(Δ[Cl2])/(Δt) Cl2O2 | 1 | 1 | (Δ[Cl2O2])/(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[O2])/(Δt) = -(Δ[Cl2])/(Δt) = (Δ[Cl2O2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| oxygen | chlorine | Cl2O2 formula | O_2 | Cl_2 | Cl2O2 name | oxygen | chlorine | IUPAC name | molecular oxygen | molecular chlorine |

| oxygen | chlorine | Cl2O2 molar mass | 31.998 g/mol | 70.9 g/mol | 102.9 g/mol phase | gas (at STP) | gas (at STP) | melting point | -218 °C | -101 °C | boiling point | -183 °C | -34 °C | density | 0.001429 g/cm^3 (at 0 °C) | 0.003214 g/cm^3 (at 0 °C) | surface tension | 0.01347 N/m | | dynamic viscosity | 2.055×10^-5 Pa s (at 25 °C) | | odor | odorless | |