CHEMISTRY COMMUNITY

I understand that the reactants are 1 because they are solid and liquid but why do only the aqueous molecules in the product stay in the answer? Is there a certain rule? I know that there is a similar rule for keeping gases when in the reactants.

The main rule is that liquids and solids are not included in the equilibrium constant expression. Aqueous solutions and gases are included.

Solids and liquids are regarded with a value 1 because their effective concentrations stay the same throughout the reaction.

I'm not entirely sure either, but I think aqueous reactants/products may stay in because they are still reacting significantly to reactants/products (aqueous just means in water). This is contrasting to pure water, which you don't include, that the solute is mixed in. There is so much solvent (water) that any change in solvent concentration would be insignificant because there is still so much pure liquid water. However, any change in solute concentration is significant.