## solids/liquids

Katie Bart 1I
Posts: 104
Joined: Sat Aug 24, 2019 12:16 am

### solids/liquids

Why are solids and liquids not included in calculating the equilibrium constant? Are only gases and aqueous solutions considered in the K value?

BritneyP- 2c
Posts: 101
Joined: Sat Sep 14, 2019 12:15 am

### Re: solids/liquids

solids are not considered because they don't have a concentration, they have density. Liquids do not affect the reactant amount at equilibrium, so they are not considered in the equilibrium constant.

Christineg1G
Posts: 115
Joined: Fri Aug 09, 2019 12:15 am
Been upvoted: 1 time

### Re: solids/liquids

Gases and aqueous solutions would only be used and considered in equilibrium expressions since the concentration of pure solids and liquids does not change.

Caitlyn Tran 2E
Posts: 100
Joined: Fri Aug 09, 2019 12:15 am

### Re: solids/liquids

Another way to think about this is that the equilibrium constant is the ratio between the products and the reactants. Since the concentration of a solid (since solids do not have a concentration) and the concentration of a pure liquid/solvent do not change, including them in the ratio would mean that the same value would be put in the numerator and denominator, thus causing them to cancel each other out. Hence, we just leave these out when calculating K.

Joanne Lee 1J
Posts: 100
Joined: Thu Jul 25, 2019 12:15 am

### Re: solids/liquids

Solids and liquids are not counted in the equilibrium constant because the concentration does not change in either the products or reactants. Therefore, yes only gases and aqueous solutions are included when trying to find K.