H2O + Li2O2 = O2 + LiOH

H_2O water + Li_2O_2 lithium peroxide ⟶ O_2 oxygen + LiOH lithium hydroxide

Balance the chemical equation algebraically: H_2O + Li_2O_2 ⟶ O_2 + LiOH Add stoichiometric coefficients, c_i, to the reactants and products: c_1 H_2O + c_2 Li_2O_2 ⟶ c_3 O_2 + c_4 LiOH Set the number of atoms in the reactants equal to the number of atoms in the products for H, O and Li: H: | 2 c_1 = c_4 O: | c_1 + 2 c_2 = 2 c_3 + c_4 Li: | 2 c_2 = 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_3 = 1 and solve the system of equations for the remaining coefficients: c_1 = 2 c_2 = 2 c_3 = 1 c_4 = 4 Substitute the coefficients into the chemical reaction to obtain the balanced equation: Answer: | | 2 H_2O + 2 Li_2O_2 ⟶ O_2 + 4 LiOH

+ ⟶ +

water + lithium peroxide ⟶ oxygen + lithium hydroxide

Construct the equilibrium constant, K, expression for: H_2O + Li_2O_2 ⟶ O_2 + LiOH 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: 2 H_2O + 2 Li_2O_2 ⟶ O_2 + 4 LiOH 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 H_2O | 2 | -2 Li_2O_2 | 2 | -2 O_2 | 1 | 1 LiOH | 4 | 4 Assemble the activity expressions accounting for the state of matter and ν_i: chemical species | c_i | ν_i | activity expression H_2O | 2 | -2 | ([H2O])^(-2) Li_2O_2 | 2 | -2 | ([Li2O2])^(-2) O_2 | 1 | 1 | [O2] LiOH | 4 | 4 | ([LiOH])^4 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 = ([H2O])^(-2) ([Li2O2])^(-2) [O2] ([LiOH])^4 = ([O2] ([LiOH])^4)/(([H2O])^2 ([Li2O2])^2)

Construct the rate of reaction expression for: H_2O + Li_2O_2 ⟶ O_2 + LiOH 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: 2 H_2O + 2 Li_2O_2 ⟶ O_2 + 4 LiOH 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 H_2O | 2 | -2 Li_2O_2 | 2 | -2 O_2 | 1 | 1 LiOH | 4 | 4 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 H_2O | 2 | -2 | -1/2 (Δ[H2O])/(Δt) Li_2O_2 | 2 | -2 | -1/2 (Δ[Li2O2])/(Δt) O_2 | 1 | 1 | (Δ[O2])/(Δt) LiOH | 4 | 4 | 1/4 (Δ[LiOH])/(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 = -1/2 (Δ[H2O])/(Δt) = -1/2 (Δ[Li2O2])/(Δt) = (Δ[O2])/(Δt) = 1/4 (Δ[LiOH])/(Δt) (assuming constant volume and no accumulation of intermediates or side products)

| water | lithium peroxide | oxygen | lithium hydroxide formula | H_2O | Li_2O_2 | O_2 | LiOH Hill formula | H_2O | Li_2O_2 | O_2 | HLiO name | water | lithium peroxide | oxygen | lithium hydroxide IUPAC name | water | dilithium peroxide | molecular oxygen | lithium hydroxide

| water | lithium peroxide | oxygen | lithium hydroxide molar mass | 18.015 g/mol | 45.9 g/mol | 31.998 g/mol | 23.95 g/mol phase | liquid (at STP) | | gas (at STP) | solid (at STP) melting point | 0 °C | | -218 °C | 462 °C boiling point | 99.9839 °C | | -183 °C | density | 1 g/cm^3 | 2.31 g/cm^3 | 0.001429 g/cm^3 (at 0 °C) | 1.46 g/cm^3 surface tension | 0.0728 N/m | | 0.01347 N/m | dynamic viscosity | 8.9×10^-4 Pa s (at 25 °C) | | 2.055×10^-5 Pa s (at 25 °C) | odor | odorless | | odorless | odorless