Acid-base chemistry is the study of substances that can donate or accept protons (H⁺ ions). Acids, like hydrochloric acid (HCl), release protons in solution, while bases, such as sodium hydroxide (NaOH), accept protons. The strength of an acid or base is determined by its ability to dissociate in water, with strong acids and bases fully dissociating and weak ones only partially dissociating. The pH scale measures the acidity or basicity of a solution, ranging from 0 to 14. A pH of 7 is neutral, indicating equal concentrations of H⁺ and OH⁻ ions. Values below 7 represent acidic solutions, while values above 7 indicate basic solutions. Understanding acid-base chemistry is essential in various fields, including biochemistry, environmental science, and medicine.