Question

What are reversible and irreversible changes? Give one example for each.

Answer 1

Hint: All the changes around us are either reversible changes or irreversible changes. Some changes can be slow while the others can be fast. It is observed that physical changes are mostly reversible and the chemical changes are mostly irreversible (not all).

Complete answer:
Reversible changes: The changes which can be reversed or can be brought back to its original form by changing the conditions, are known as reversible changes. It is observed that most physical changes are reversible. Reversible changes are slow. We can say that all reversible changes are temporary changes that can be reversed.
There are many examples of reversible changes- Inflating a balloon (Balloon regains its original shape after evacuating), Stretching of a rubber band, Melting of wax etc.
Irreversible changes: The changes that can’t be reversed contrary to reversible changes are known as irreversible changes. These changes are permanent changes. It is usually observed that many chemical reactions are irreversible. In irreversible change new products are formed in large amounts. These changes are mainly fast.
There are many examples of irreversible changes- Burning a piece of paper ( paper will burn to form ashes that can’t be reversed), Cooking of food, mixing substances can also cause irreversible change, bursting of balloons etc.

Note :
It is not very difficult to identify which process is reversible and which one is irreversible. If the substance can be brought back to its initial form, it’ll be a reversible process and if not then the process will be irreversible.