Question

Give two examples of Irreversible change

Answer 1

$\huge\mathfrak{Irreversible\:changes}$

• The changes which cannot be brought about by reversing the opposite conditions are called irreversible changes.
• In an irreversible change, often new substances are formed.
• Examples -

1. Burning of paper [ As we cannot get paper back ]
2. Cooking of food [ We cannot get back raw vegetables from  cooked vegetables]

$\huge\mathfrak{Reversible\:changes}$

• The changes which can be brought about by reversing the opposite conditions are called reversible changes
• In a reversible change. often no new substances are formed
• Examples - All changes in state of matter

Answer 2

$\bold{\underline{\underline{Answer:}}}$

$\bold{\sf{\blue{Irreversible\:Changes}}}$

• What is irreversible change?

The changes in which a substance(s) is converted into a new substance(s), possessing properties altogether different from the original ones is called an $\bold{\sf{\pink{irreversible\:change}}}$

During such change, the original substance cannot be recovered by any simple means. Usually such changes are permanent.

$\bold{\large{\sf{\green{Examples:}}}}$

When carbon is burnt, carbon dioxide $\bold{CO_2}$ is formed. In this process carbon combines with oxygen, therefore carbon and oxygen are reactants ,while carbon dioxide $\bold{CO_2}$ is a product.

Let's take another example to understand this much better.

When a magnesium wire is burnt in air, a white powder of magnesium oxide is formed. We cannot obtain magnesium from magnesium oxide by simple methods. Properties of magnesium oxide are altogether different from those of magnesium. A new substance $\bold{MgO}$ is formed. Hence this is an irreversible change.