Chemical Change:
A chemical change refers to a process in which one or more substances are transformed into new substances with different chemical properties. It involves the breaking and forming of chemical bonds, resulting in the creation of new molecules or compounds. This change is typically accompanied by the release or absorption of energy in the form of heat, light, or sound. Chemical changes are also referred to as chemical reactions.

Irreversible Change:
An irreversible change, on the other hand, is a type of change that cannot be undone or reversed to restore the original substances. Once an irreversible change occurs, it is permanent and cannot be reversed by physical or chemical means alone. Irreversible changes often involve a significant alteration in the physical or chemical properties of a substance.

Differences:

1. Nature of Change:
- Chemical Change: A chemical change involves the formation of new substances with different chemical properties. It results in the creation of new molecules or compounds.
- Irreversible Change: An irreversible change involves a permanent alteration in the physical or chemical properties of a substance. It cannot be undone or reversed.

2. Process:
- Chemical Change: Chemical changes occur through chemical reactions, where chemical bonds are broken and formed to create new substances.
- Irreversible Change: Irreversible changes can occur through various processes, such as heating, cooling, mixing, or reacting substances. They may involve physical changes, chemical reactions, or a combination of both.

3. Reversibility:
- Chemical Change: Chemical changes are generally reversible through additional chemical reactions. The original substances can often be obtained again by reversing the reaction conditions.
- Irreversible Change: Irreversible changes cannot be reversed by physical or chemical means alone. The original substances cannot be restored.

4. Energy Changes:
- Chemical Change: Chemical changes often involve the release or absorption of energy in the form of heat, light, or sound. This energy change is a characteristic feature of chemical reactions.
- Irreversible Change: Irreversible changes may or may not involve significant energy changes. The alteration in physical or chemical properties can occur with or without energy release or absorption.

In summary, a chemical change refers to the transformation of substances into new substances with different chemical properties through chemical reactions. On the other hand, an irreversible change is a permanent alteration in the physical or chemical properties of a substance that cannot be reversed. While all chemical changes are irreversible, not all irreversible changes involve chemical reactions.

chemical changes are the changes in which new substances are formed, for example- curdling if milk results in the formation of new substances irreversible changes are the changes which can not be reversed ,for example- burning of a paper is irreversible change as the burned paper is not be reversed .