Final answer:
Acids are substances that can donate a proton, with strong acids like HCl completely dissociating in water. Bases can accept a proton, with examples like NaOH being strong bases. Weak acids and bases, like acetic acid and ammonia, do not completely dissociate in water.
Step-by-step explanation:
Acids and Bases Definitions
An acid is a substance that can donate a hydrogen ion (H+) or proton in solution, and a base is a substance that can accept a hydrogen ion (H+). The strength of an acid or base refers to its ability or tendency to lose or gain a proton.
Strong acids and strong bases almost completely dissociate in water, meaning they donate or accept protons very easily. Examples of strong acids include hydrochloric acid (HCl) and sulfuric acid (H2SO4), while examples of strong bases include sodium hydroxide (NaOH) and potassium hydroxide (KOH).
In contrast, weak acids and weak bases only partially dissociate in water. This means they do not completely release their hydrogen ions or accept protons in solution. Acetic acid (CH3COOH) is an example of a weak acid, while ammonia (NH3) is an example of a weak base.
Identifying Acids and Bases
The Arrhenius definition of an acid is a substance that increases the concentration of hydronium ions (H3O+) when dissolved in water, and an Arrhenius base is one that increases the concentration of hydroxide ions (OH-) in water.
The Brønsted-Lowry definition expands on this by saying an acid is a proton donor and a base is a proton acceptor, not necessarily just in water. This helps identify conjugate acid-base pairs in an acid-base reaction, which are the substances formed when an acid loses a proton and the substance formed when a base gains a proton.