The reaction of water with other substances is known as hydrolysis. Hydrolysis is a chemical process in which water molecules break apart and interact with other molecules, resulting in the cleavage of chemical bonds and the formation of new chemical compounds. It involves the addition of water (H2O) to a compound and the splitting of its chemical bonds, usually resulting in the formation of two new molecules.

Hydrolysis reactions are found throughout chemistry and biochemistry. For example:

- In acid-base chemistry, hydrolysis occurs when water reacts with an acid or base to form hydronium (H3O+) or hydroxide (OH-) ions.

- In biochemistry, hydrolysis is a fundamental process in digestion, where enzymes break down complex molecules such as carbohydrates, proteins, and fats by adding water molecules and breaking specific chemical bonds.

- Hydrolysis is also vital in soap making, where fats and oils are hydrolyzed to form fatty acids and glycerol.

- In industrial processes, hydrolysis is employed to break down polymers and produce various chemicals and materials.