Solids and Liquids

[805383532]

Why are solids and liquids disregarded when calculating K and Q?

[Kimberly Koo 2I]

The change in solvent concentration is insignificant, which is why pure liquids are eliminated from the equilibrium expression.

[William Chan 1D]

Solids and liquids are essentially non-compressible, so their concentrations don't really change. Gas concentrations or ion concentrations will change though, those are the values we calculate for.

[Matt F]

Most solids and liquids are pure substances, meaning their molar concentration does not change in the reaction. Therefore, it will not affect the equilibrium concentrations of other reactants/products

[Viviana Velasquez]

Lavelle mentioned that it had something to do with their concentrations not changing so they were insignificant.

[Chris Charton 1B]

Pure solids and liquids do not affect reactant amounts in the equation so they are not included in the equation. If you included them they would have an activity level of 1, thus not changing the equation.

[RobertXu_2J]

Because changes to their concentration are inconsequential for the rate of reaction. Solids just sit there, they don't really have a concentration because they don't mix with the solvent. Liquids are the solvent, so you assume that there will always be enough of it that any decrease will be insignificant for the rate of reaction.