O2 + Ba = BaO2

oxygen + barium ⟶ barium peroxide

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

+ ⟶

oxygen + barium ⟶ barium peroxide

K_c = [BaO2]/([O2] [Ba])

rate = -(Δ[O2])/(Δt) = -(Δ[Ba])/(Δt) = (Δ[BaO2])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| oxygen | barium | barium peroxide Hill formula | O_2 | Ba | BaO_2 name | oxygen | barium | barium peroxide IUPAC name | molecular oxygen | barium | barium(+2) cation peroxide

| oxygen | barium | barium peroxide molar mass | 31.998 g/mol | 137.327 g/mol | 169.325 g/mol phase | gas (at STP) | solid (at STP) | solid (at STP) melting point | -218 °C | 725 °C | 450 °C boiling point | -183 °C | 1640 °C | density | 0.001429 g/cm^3 (at 0 °C) | 3.6 g/cm^3 | 4.96 g/cm^3 solubility in water | | insoluble | slightly soluble surface tension | 0.01347 N/m | 0.224 N/m | dynamic viscosity | 2.055×10^-5 Pa s (at 25 °C) | | odor | odorless | |