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Answer:
Change is constant’. Changes happen all around us, even within us. Most of them are irreversible but some of them are reversible changes. Yes. Let’s learn about reversible changes and irreversible changes and understand the difference between them with a lot of examples.
Reversible changes and Irreversible changes
All changes in the world are one of the two types – Reversible changes and irreversible changes. A change which can happen backward, that is, can be reversed is called a reversible change. If you keep water in the freezer for some time, it transforms into ice. But as soon as you take it out of the freezer, it turns into water again. This is a reversible change. Similarly, if you boil water, it evaporates and becomes water vapor. When you cool this vapor down, it turns back to water.
Explanation:
A change which cannot happen backward, that is, it cannot be reversed is called an irreversible change. When you burn a piece of paper, it turns to ash. It cannot become paper again. Your height cannot decrease. These are irreversible changes. They cannot be reversed at all.
Reversible changes - Those changes which can be reversed or regained by altering the physical conditions such as temperature, pressure, etc.
e.g Melting of ice, Expansion of metal , Inflation of balloon, etc
Irreversible changes - These are the changes which once occurred cannot be reversed or regained (because a completely new substance is formed) even by changing physical or chemical conditions.
eg. Burning or candle, Formation of curd from milk, rusting of iron.
● The expansion of metal, which is a reversible change can be put into good use as in Iron rims are fixed on wooden wheels of carts. Iron rims are heated. The thermal expansion allows them to slip over the wooden wheel. Water is poured on it to cool. The rim contracts and becomes tight over the wheel.
Hope this helps !