11.11 Part b

[Michelle Dong 1F]

A 0.10 mol sample of pure ozone, O3, is placed in a sealed 1.0-L container and the reaction 2O3 (g) --> <-- 3O2 (g) is allowed to reach equilibrium. A 0.50 sample of pure ozone is placed in a second 1.0-L container at the same temperature and allowed to reach equilibrium. Without doing any calculations, predict which of the following will be different in the two containers at equilibrium. Which will be the same?
(b) Concentration of O2

The answer key says this will be different (the second sample will have a larger concentration of O2) -- can someone explain why?

[Johann Park 2B]

Knowing that the volume of the containers are the same, we only have to look at the amount of O₂ in each container. Our products and reactants are the same in both containers, and only the amount (moles) of O₃ changes from .10 to .50 -> therefore, O₂ will also have more moles in container 2 than in container 1. With more moles in the same volume container (Concentration = mol/L), the concentration is larger.

[Clara Rehmann 1K]

There's more O2 in the same size space (.1 mol in one L vs. .5 mol in one L), thus the second container will always have a higher concentration of O2.