Pure Liquids and Pure Solids

Moderators: Chem_Mod, Chem_Admin

Nathan Mariano 2G
Posts: 51
Joined: Thu Sep 27, 2018 11:29 pm

Pure Liquids and Pure Solids

Postby Nathan Mariano 2G » Mon Jan 14, 2019 1:00 am

Pure liquids and pure solids are able to react in chemical reactions. Therefore, I do not completely understand the reason why pure liquids and pure solids are not contained in the equilibrium constant. Can someone explain this to me?

kateminden
Posts: 48
Joined: Thu Sep 27, 2018 11:24 pm

Re: Pure Liquids and Pure Solids

Postby kateminden » Mon Jan 14, 2019 1:48 am

Pure liquids and pure solids are not included in equilibrium constant expression because their densities (and, therefore, concentrations) are constant, so they do not affect the reactant/product amount at equilibrium.

Anusha 1H
Posts: 53
Joined: Thu Sep 27, 2018 11:15 pm

Re: Pure Liquids and Pure Solids

Postby Anusha 1H » Mon Jan 14, 2019 11:37 am

Because the molar concentrations of solids and liquids don't change during a reaction, they are not included in calculating the K value

Chem_Mod
Posts: 16489
Joined: Thu Aug 04, 2011 12:53 pm
Has upvoted: 349 times

Re: Pure Liquids and Pure Solids

Postby Chem_Mod » Mon Jan 14, 2019 1:21 pm

The activities of pure liquids and solids are technically included in the equilibrium constant, but their activities do not change during the reaction, so the value of 1 is accurately used for their activities (or concentrations).

Nina Do 4L
Posts: 49
Joined: Thu Sep 27, 2018 11:27 pm

Re: Pure Liquids and Pure Solids

Postby Nina Do 4L » Mon Jan 14, 2019 8:22 pm

Pure solids or liquids aren't included in the equilibrium expression because their concentrations stay constant throughout the reaction so we don't include them.

Rian Montagh 2K
Posts: 48
Joined: Thu Sep 27, 2018 11:15 pm

Re: Pure Liquids and Pure Solids

Postby Rian Montagh 2K » Tue Jan 15, 2019 3:01 pm

I'm still confused about this concept. For example, with the reaction CaCO3(s) <--> CaO(s) + CO2(g), how do the molar concentrations of the solids not change?


Return to “Equilibrium Constants & Calculating Concentrations”

Who is online

Users browsing this forum: No registered users and 1 guest