The chemical equation for the dissolution of calcium hydroxide, Ca(OH)₂, in water is:
Ca(OH)₂ (s) → Ca2+ (aq) + 2OH– (aq)
When calcium hydroxide is added to water, it dissociates into calcium ions (Ca2+) and hydroxide ions (OH–). This process is essential in various applications, including adjusting the pH in swimming pools and soil treatment. Calcium hydroxide is only slightly soluble in water, which means that not all of it will dissolve, resulting in a saturated solution at equilibrium.