Question

Long Answer Questions,
1. Differentiate between physical and chemical changes with examples
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Answer 1

A chemical change results from a chemical reaction, while a physical change is when matter changes forms but not chemical identity. Examples of chemical changes are burning, cooking, rusting, and rotting. Examples of physical changes are boiling, melting, freezing, and shredding.

Answer 2

Answer:

There are many differences between physical and chemical changes and it is important to understand them to be able to understand these concepts clearly. The comparisons and differences between physical and chemical changes are given below along with their examples. To understand physical and chemical properties and changes better, it is important to know what they are. Visit physical and chemical changes to know more about them in detail. In this article, the differences between physical changes and chemical changes are provided in a tabular format.

Differences Between Physical and Chemical Change

Physical Change Chemical Change

When a substance undergoes a physical change, its composition remains the same despite its molecules being rearranged. When a substance undergoes a chemical change, its molecular composition is changed entirely. Thus, chemical changes involve the formation of new substances.

Physical change is a temporary change. A chemical change is a permanent change.

A Physical change affects only physical properties i.e. shape, size, etc. Chemical change both physical and chemical properties of the substance including its composition

A physical change involves very little to no absorption of energy. During a chemical reaction, absorption and evolution of energy take place.

Some examples of physical change are freezing of water, melting of wax, boiling of water, etc. A few examples of chemical change are digestion of food, burning of coal, rusting, etc.

Generally, physical changes do not involve the production of energy. Chemical changes usually involve the production of energy (which can be in the form of heat, light, sound, etc.)

In a physical change, no new substance is formed. A chemical change is always accompanied by one or more new substance(s).

Physical change is easily reversible i.e original substance can be recovered. Chemical changes are irreversible i.e. original substance cannot be recovered.

Thus, it can be understood that the primary difference between physical and chemical changes is that physical changes are reversible whereas chemical changes are usually not. To learn more about how physical and chemical changes