5G.9c, d, e

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Michelle Song 1G
Posts: 30
Joined: Wed Nov 14, 2018 12:23 am

5G.9c, d, e

Postby Michelle Song 1G » Wed Jan 09, 2019 5:24 pm

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-mol 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? Briefly explain your answers.

a) amount of O2

b) concentration of O2

c) ratio of [O2]/[O3]

d) the ratio [O2]^3/[O3]^2

e) the ratio [O3]^2/[O2]^3

According to the solutions manual, the ratio of [O2]/[O3] is not the same but the ratio [O2]^3/[O3]^2 and the ratio [O3]^2/[O2]^3 are the same for both containers. I am confused because I thought that the ratio of [O2]/[O3] would be the same because there should be 2 moles of O3 for every 3 moles of O2. The solution manual says that K is a constant and therefore the ratio [O2]^3/[O3]^2 and the ratio [O3]^2/[O2]^3 are the same but I do not understand why or how the math works out if the concentration is changed.

Samantha Hoegl Roy 2C
Posts: 81
Joined: Fri Sep 28, 2018 12:15 am

Re: 5G.9c, d, e

Postby Samantha Hoegl Roy 2C » Wed Jan 09, 2019 5:37 pm

the ratio of [O2]/[O3] is not the same because it is not balanced. It is therefore not K and just represents the concentration of both O2 and O3 present. since both samples have different concentrations, [O2]/[O3] cannot be the same

Matthew Mar 1J
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Joined: Fri Sep 28, 2018 12:15 am
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Re: 5G.9c, d, e

Postby Matthew Mar 1J » Wed Jan 09, 2019 7:23 pm

The ratio [O2]^3/[O3]^2 and the ratio [O3]^2/[O2]^3 factor in the coefficients from the equation which represent the actual ratio of products to reactants involved in the reaction. These ratios are also the equilibrium constants for the forward and reverse reactions and equilibrium constants are always the same, regardless of the starting concentrations.

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