What Happens to an Acid or a Base in a Water Solution?
This section elaborates on the behavior of acids and bases in water, focusing on their ionization processes. It begins by demonstrating through an activity that hydrochloric acid (HCl) produces hydrogen ions only in an aqueous solution; it cannot ionize in a dry state, highlighting the role of water in these transformations. The significance of writing hydrogen ions as H+(aq) or as hydronium ions (H3O+) is explained to reflect their interaction with water.
When acids like HCl or H2SO4 are dissolved in water, they release H+(aq) ions. Conversely, bases such as sodium hydroxide (NaOH) or potassium hydroxide (KOH) release OH– ions. Notably, an alkali is defined as a soluble base. The section also presents that when an acid and a base react, they undergo neutralization to produce salt and water.
Moreover, crucial safety notes are provided on the exothermic nature of diluting acids or bases in water, emphasizing the importance of adding acid to water rather than the reverse to avoid dangerous splashes and potential accidents. Finally, the section summarizes the process of dilution and its effects on ion concentration with respect to the fundamental principles of acid-base chemistry.