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Pure Liquids and Pure Solids

Posted: Mon Jan 14, 2019 1:00 am
by Nathan Mariano 2G
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?

Re: Pure Liquids and Pure Solids

Posted: Mon Jan 14, 2019 1:48 am
by kateminden
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.

Re: Pure Liquids and Pure Solids

Posted: Mon Jan 14, 2019 11:37 am
by Anusha 1H
Because the molar concentrations of solids and liquids don't change during a reaction, they are not included in calculating the K value

Re: Pure Liquids and Pure Solids

Posted: Mon Jan 14, 2019 1:21 pm
by Chem_Mod
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).

Re: Pure Liquids and Pure Solids

Posted: Mon Jan 14, 2019 8:22 pm
by Nina Do 4L
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.

Re: Pure Liquids and Pure Solids

Posted: Tue Jan 15, 2019 3:01 pm
by Rian Montagh 2K
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?