How do you write the K for an equation with heterogeneous equilibria?

[rita_debbaneh2G]

For example, let's say the reactants are an aqueous solution and a solid and the products are a gas and an aqueous solution?

[Bella Wachter 1A]

Solids and liquids are not included in the equilibrium constant.

If we had a mix of aqueous species and gases, we would need to convert the partial pressures of the gases into concentrations (using the Ideal Gas Law) and then use Kc (instead of Kp because we cannot convert concentrations of aqueous species into partial pressures).

If we are already given the concentrations of the gases, we simply plug them in along with the aqueous concentrations to the Kc equation.

Hope this helps!

[anikamenon2H]

You would only include the aqueous reactants and the gas and aqueous products. Solids are omitted but it otherwise follows the same format as always, the important thing is just knowing what to omit (solids and liquids).

Hope this helps!

[JonathanSung_2G]

Pure liquids and solids are not factored into the equilibrium constant expression. In your example, you will only need to use the equilibrium concentrations of the aqueous solutions and gases. Omit the solid reactant in the expression, so you would have the concentrations of both products over the concentration of the aqueous solution reactant.

[EnricoArambulo3H]

You would only factor the substances in the gaseous phase, or in an aqueous solution. You would NOT factor solids and liquids into your equilibrium constant. Hope this helped!

[Sara Sandri 2B]

If you had an aqueous and solid on the reactants side and a gas and aqueous on the products side, you must remember to omit the solids and liquids from your equilibrium constant equation. Since Kc= products/ reactants, you would write it so that Kc= (gaseous product^ its coefficient)(aqueous product^its coefficient)/(aqueous reactant^its coefficient), omitting the solid on the reactants side since it is a pure substance and its concentration does not change.

[Arezo Ahmadi 3J]

You would just not include the solid as is the standard procedure for writing out the equation. Both solids and liquids are not included in the equilibrium constant. You would, however, include the gas and aqueous solution.

[Siwa Hwang 3G]

Remember that solids do NOT have concentrations since it is not composed of solvent. So leave out solids and liquids in the equilibrium equation to find the constant. Just include the concentration or pressure of gas or aqueous solution.

[Emily Langie 3L]

Concentration is measured in mol/L, so it doesn't apply to solids. Liquids are also omitted from the equation, so you would only include the concentrations of gas or aqueous solutions.

[James Fu 2F]

I believe that we do not include solids and gasses when calculating the equilibrium constant. This is because the molar concentration of pure substances such as solids or liquids does not significantly alter or change the amount of product or reactant in a reaction.

[Nan_Guan_1L]

you would only need to consider the aq formed components. gases and solids would not be considered!