Hydrolysis
Definition and meaning of Hydrolysis in chemistry.
Hydrolysis is a chemical reaction in which a compound reacts with water and splits into two or more products, with one fragment gaining a hydrogen atom (H) and the other gaining a hydroxyl group (OH) from the water molecule.
In more detail
Hydrolysis is the reverse of a condensation (dehydration) reaction, which joins two molecules and releases water. It occurs across chemistry: acids, bases, and enzymes called hydrolases speed up hydrolysis of proteins, carbohydrates, lipids, and nucleic acids in living cells, while in aqueous solution, salts of weak acids or weak bases undergo hydrolysis with water, shifting the pH of the solution. Because it breaks a covalent bond using the elements of water, hydrolysis is classified as a type of decomposition reaction.
Key facts
| Reaction type | Decomposition by addition of water |
|---|---|
| Reverse process | Condensation (dehydration synthesis) |
| Common catalysts | Acids, bases, hydrolase enzymes |
| Field | General Chemistry |
Sucrose (C12H22O11) undergoes hydrolysis in water, catalyzed by dilute acid or the enzyme sucrase, to form glucose and fructose: C12H22O11 + H2O to C6H12O6 + C6H12O6.
Frequently asked questions
How is hydrolysis different from dehydration synthesis?
Hydrolysis breaks a bond by adding the H and OH of water, splitting one molecule into two; dehydration synthesis does the opposite, joining two molecules into one and releasing a water molecule.
Why can hydrolysis of a salt change a solution's pH?
If a salt comes from a weak acid or weak base, one of its ions reacts with water (hydrolyzes) to produce extra H3O+ or OH- ions, making the resulting solution acidic or basic rather than neutral.