Question

How will you confirm that a colourless liquid given to you is pure water?

Answer 1

Answer:

To confirm that a colourless liquid given to us is pure water we have to boil it.

As we know the boiling point and freezing point of the water are $100°\mathrm{C}$or $373\mathrm{K}$ and $0°\mathrm{C}$or $273\mathrm{K}$at one atmosphere of pressure.

If any impurities are present in water it will change the boiling point of water and it will not boil at sharp$100°\mathrm{C}$.

Conclusion:

So, to confirm that a colourless liquid given to us is pure water we have to boil it.

If its boiling point is sharp $100°\mathrm{C}$ means it is pure water and no impurities are present.