Question

Define of reversible and irreversible changes

Answer 1

A reversible change is a physical change that can be undone. A final substance can be converted back to the original substance without creating any new material. Freezing, melting, dissolving, boiling, evaporating and condensing are reversible changes.


Irreversible changes are permanent changes that cannot be undone.

Answer 2

Reversible changes are the changes which can be reversed and are also known as physical changes.

For example- boiling of water, etc

When we boil water it get converted into water vapour by the process of evaporation. We can again obtain water in its liquid form by the process of condensation. So this is a reversible change.


Irreversible changes are the changes which cannot be reversed and are also known as chemical changes.

For example-- burning of wood, cooking vegetables etc.

When we burn wood it gets converted into ashes. Wood cannot be obtained again from these ashes. Hence it is an irreversible change.