Osmosis video - Definitions of acids and bases

Acids are chemicals that release hydrogen ions (H+) when dissolved in water. Bases are compounds that release hydroxide ions (OH-) when dissolved in water. Acids and bases are classified as strong or weak based on how they dissociate in solutions. Strong acids and bases completely dissociate in water, releasing all their H+ or OH- ions. Weak acids and bases only partially dissociate, releasing some but not all of their H+ or OH- ions.

The pH scale measures how acidic or basic a solution is. The lower the pH, the more acidic the solution; the higher the pH, the more basic the solution. Pure water has a pH of 7, which is considered neutral. Many chemists tried to describe acids and bases and proposed various theories. Some of these chemists are Arrhenius, Bronsted, and Lowry.