Final answer:
A molecule that donates a hydrogen ion is called a Brønsted-Lowry acid. This theory differentiates acids and bases based on their ability to donate or accept protons, which is central to acid-base reactions. The naming of acids takes into account their forming of protons and anions in solution.
Step-by-step explanation:
A molecule that is capable of releasing or donating a hydrogen ion is termed a Brønsted-Lowry acid. According to the Brønsted-Lowry theory, an acid is defined as a compound that donates a proton (hydrogen ion, H+) to another compound, whereas a base accepts this proton. The naming of acids varies depending on whether they have oxyanions or not.
For example, when an acid like HCl disassociates in water, it donates a proton, forming hydronium ions (H3O+), and thus acts as a Brønsted-Lowry acid:
HCl(aq) + H2O(l) → H3O+(aq) + Cl−(aq)
The most common examples of bases, such as NaOH or Ca(OH)2, contain the hydroxide ion (OH−), which can accept a proton to form water.