solids in calculating equilibrium constant? [ENDORSED]

josephyim1L
Posts: 61
Joined: Fri Sep 28, 2018 12:15 am

solids in calculating equilibrium constant?

Are solids included in the calculation for the equilibrium constant when using partial pressure?

Cienna Henry 1J
Posts: 61
Joined: Fri Sep 28, 2018 12:15 am
Been upvoted: 1 time

Re: solids in calculating equilibrium constant?

No, pure solids and liquids are excluded in the calculation

Edward Xie 2E
Posts: 63
Joined: Fri Sep 28, 2018 12:23 am

Re: solids in calculating equilibrium constant?  [ENDORSED]

As Dr. Lavelle said,

Molar concentration of a pure substance (solid or liquid) does not change in a reaction
∴ solids and liquids are not included in K expression

Sydney Tay 2B
Posts: 64
Joined: Fri Sep 28, 2018 12:20 am

Re: solids in calculating equilibrium constant?

Pure solids and liquids are not included in calculating the equilibrium constant, but aqueous solutions and gases are included.

Edward Suarez 1I
Posts: 75
Joined: Fri Sep 28, 2018 12:27 am

Re: solids in calculating equilibrium constant?

only aq and g solutions are included in the equation (and g is in partial pressure)

uhedlund
Posts: 38
Joined: Wed Nov 15, 2017 3:03 am

Re: solids in calculating equilibrium constant?

No, only aqueous solutions and gases are included in calculating the equilibrium constant.

Luc Lorain 1L
Posts: 59
Joined: Fri Sep 28, 2018 12:18 am

Re: solids in calculating equilibrium constant?

Edward Suarez 1I wrote:only aq and g solutions are included in the equation (and g is in partial pressure)

It should also be expanded that when reactions are completed in a fixed volume container, the addition of noble (inert) gases does not affect equilibrium for similar reasons as pure solids and liquids: they do not affect the concentration of reactant/product.

allisoncarr1i
Posts: 60
Joined: Fri Sep 28, 2018 12:15 am

Re: solids in calculating equilibrium constant?

Does anyone know why they are not included or is it not necessary to know why?

Yiting_Gong_4L
Posts: 69
Joined: Fri Sep 28, 2018 12:25 am

Re: solids in calculating equilibrium constant?

Solids and liquids are NOT included when calculating the equilibrium constant because a solids concentration would be 100% which is just 1 and doesn't affect the answer.
Only aqueous solutions and gases are included in the calculation of the equilibrium constant.