Solids and Liquids

[briannam_1F]

Can someone further explain why we leave out solids and liquids when calculating K?

[sarahsalama2E]

Solids and Liquids are left out when writing the equilibrium expressions because essentially their concentrations stay the same during the reaction. Also, pure substances such as pure liquids and pure solids are left out when writing equilibrium expressions because their concentrations can't change. An example of a pure substance, in particular, a pure liquid, is water.

[Brianna Becerra 1B]

Liquids are omitted when calculating the equilibrium constant because when there is a solvent, the concentration does not change since there is such a large excess making it insignificant to the calculation. Solids are not used because they do not have molar concentrations.

[AlyshaP_2B]

During lecture, Lavelle said solids are excluded because they don't have molar concentrations, and liquids are excluded because the solvent concentration stays the same.

[Harry Zhang 1B]

They are not included because they are not dissolved and hence their concentration is constant or cannot be calculated. Even if you put some more pure solid or some more pure liquid into the solution, you are just increasing the amount of such solid or liquid but their concentration does not change.

[SarahCoufal_1k]

You omit them because there is usually so much excess that the actual amount then used is insignificant in terms of molar concentration.

[005321227]

The reason solids are not used in equilibrium reactions is because their concentrations stay constant throughout the reaction

[Max Madrzyk Dis 4G]

Solids and liquids are not included because their concentrations stay the same throughout the reaction so there is no need to calculate the change.