Pure Solids and Liquids

[Sara Lakamsani 4D]

I still don't quite understand why we discount pure solids and liquids. Can someone help explain?

[Yvonne Du]

My TA said they dont affect equilibrium

[paytonm1H]

My understanding is that because pure liquids remain extremely dilute and solids barely dissociate, their effects on equilibrium are disregarded. Therefore they are not included in the equilibrium constant.

[Sara Lakamsani 4D]

Thank you guys for your responses!

[Maayan Epstein 14B]

It is similar to how we do pseudo rate constants. We make one reactant so large that it basically doesn't affect the reaction rate, enabling us to just study the other reactant as if it is the only thing that affects the rate. Same thing with liquids and solids. They are in such high excess that they do not affect the rate, so you look to the other aquesous components because those are the limiting factors that affect equilibrium and rate.