Difference between physical change and chemical change?

Question

Answer

Physical change is a change in which a process can be reversed like melting of ice, boiling water etc...
Chemical change is a change in which a process can not be reversed like rusting of iron,
growing of a plant etc.

Answer

A change in which no new substance are formed and can be reversed is called physical change . e.g melting of ice whereas a change in which new substance are formed and can't be reversed is called chemical change. e.g burning of paper

Answer

Physical Change:
A physical change refers to a process in which the state or appearance of a substance is altered without changing its chemical composition. It is a reversible change where the original substance can be restored by simple physical methods. Physical changes do not involve the formation of new substances and do not result in a change in the chemical properties of the material.

Examples of Physical Changes:
1. Change in state: Melting of ice to form water or freezing of water to form ice.
2. Changes in size or shape: Cutting a piece of paper, breaking a glass, or crushing a can.
3. Changes in appearance: Dissolving salt in water, mixing different colored paints to form a new color, or melting wax to form a liquid.

Characteristics of Physical Change:
1. No new substances are formed.
2. The change is usually reversible.
3. The mass of the substance remains the same.
4. The change can often be observed without the need for specialized equipment.

Chemical Change:
A chemical change, also known as a chemical reaction, occurs when one or more substances are transformed into new substances with different chemical properties. It involves the breaking and formation of chemical bonds, resulting in the rearrangement of atoms and the creation of new compounds. Chemical changes are usually irreversible and require specific conditions such as heat, light, or the presence of a catalyst to occur.

Examples of Chemical Changes:
1. Combustion: Burning of wood, paper, or gasoline.
2. Oxidation: Rusting of iron or tarnishing of silver.
3. Decomposition: Decomposition of organic matter or digestion of food.
4. Precipitation: Formation of a solid precipitate when two solutions are mixed.

Characteristics of Chemical Change:
1. New substances with different properties are formed.
2. The change is usually irreversible.
3. The mass of the substances involved may change due to the formation of new compounds.
4. The change often requires specific conditions such as heat, light, or the presence of a catalyst.

Summary:
In summary, physical changes involve alterations in the state, shape, or appearance of a substance without changing its chemical composition, while chemical changes result in the formation of new substances with different chemical properties. Physical changes are reversible, do not involve the formation of new compounds, and can often be observed without specialized equipment. On the other hand, chemical changes are usually irreversible, involve the breaking and formation of chemical bonds, and require specific conditions to occur. Understanding the difference between physical and chemical changes is essential in various fields, including chemistry, physics, and everyday life applications.

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