Difference Between Physical And Chemical Change

Difference Between Physical And Chemical Change: Our environment is continuously changing and different processes are taking place in it. Some of the changes that take place lead to changes in the state of the matter whereas in some of the processes, completely new matter is formed. Depending upon the nature of the change, these changes can be broadly classified as physical and chemical changes. In this article, we will discuss physical and chemical change and their differences.

Difference Between Physical and Chemical Change:

Basis of Difference	Physical Change	Chemical Change
Definition	Change in which the physical properties of the matter are not changed is called physical change.	Change which leads to a change in the chemical properties of the matter is called chemical change.
Nature of Change	Physical change is temporary in nature and the change brought can be reversed using simple physical processes.	Chemical change is permanent in nature and cannot be reversed.
Energy Absorption	Physical change may or may not absorb energy.	If energy is absorbed during chemical change it is called endothermic in nature.
Release of Energy	No energy is released in physical change.	A chemical change may lead to the release of energy and such a change is called exothermic reaction.
Properties	The chemical properties of the products are the same as the matter that constitutes the product.	The physical and chemical properties of the products are completely different from the reactants.
Mass of Products	The mass of products is the same as that of the reactants.	The mass of products may or may not be the same as the mass of reactants.
Effect of Change	It leads to changes in the physical properties of matter such as temperature, state, etc.	It leads to a change in the physical and chemical properties of the matter due to the formation of new bonds.
Example	Melting of ice, Evaporation of water, etc.	Burning of paper, Alloy formation, etc.

Physical Change:

Change in which the chemical composition of the matter does not change but leads to change in the state of matter only is termed as physical change. The molecular composition of the matter remains the same and no new product formation takes place in physical change. There is no change in energy during physical change. Physical change is temporary in nature and reversible as the reaction can be reversed to get back to the original state of matter. The energy required to bring a physical change is equal in magnitude to the energy required to reverse the physical change. Physical change follows conservation of mass and the mass of products is equal to the sum of reactants. The physical and chemical properties of the products are the same as the original matter. In physical change, the physical properties of matter such as temperature, state, mass, etc. Some examples of physical change are:

• Evaporation of water as water can be obtained again from steam by condensation
• Drying of clothes as they can be again made wet with water
• Freezing of water to ice as the change can be reversed on melting
• Dissolving salt in water as both salt and water can be separated by evaporation and crystallisation

Chemical Change:

Those changes which lead to a change in the chemical composition of the matter is termed chemical change. This change leads to the formation of new products with different chemical compositions. The molecular composition of matter is changed and new product formation takes place in chemical change. The chemical and physical properties of the products formed are different from the original reactants. A chemical change may be accompanied by the release or absorption of energy. Chemical change in which energy is absorbed is called endothermic reaction while the reaction in which energy is released is called exothermic reaction. The mass of products may or may not be the same as the mass of reactants due to the loss of some mass as energy. Chemical change is permanent in nature and cannot be reversed through simple physical processes. The irreversible nature of chemical change is due to the breakage and formation of new bonds that take place during a chemical change. Some examples of chemical change are:

• Burning of paper
• Burning of coal
• Reaction of sulphuric acid and sodium hydroxide
• Curdling of milk
• Breaking down of food to glucose