The ion-product constant. For the reaction:
the equilibrium expression would be:
Note that all pure liquid terms are omitted, hence H2O does not appear in the denominator. At 25 °C
Generalic, Eni. "Ion-product constant." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
Glossary
Periodic Table