Question

explain why the buring of paper is asaid to be an irreversible change whereas the boiling of water is know as a reversible change

Answer 1

Burning of paper is irreversible change as new substance(ash) is form and it is changing state of paper whereas boiling of water is reversible change as no new substance is form.
Reversible change is physical change and irreversible are chemical change.

Answer 2

Reversible and irreversible changes.

Explanation:

When the chemical nature of a substance is altered in a way that it cannot go back to its initial state without the addition or removal of extra materials,, the change is known as irreversible.

When the changes in a substance can easily be countered to return it to its original state, they are called reversible changes.

-Therefore when paper is burned, its chemical composition is completely altered which cannot be reversed in any way to give back the paper. This is the reason why the change is called irreversible.

-But when water is boiled, it merely changes its physical state and the collected water vapors from the boiling water can be condensed to obtained liquid water making the change a reversible one.