Question

Suggest a way to determine whether a colorless liquid is pure water or a salt solution

Answer 1

You could boil the liquid. If it is pure liquid than 100% of the liquid will boil off, however, if there is salt in the solution it will remain in the bottom of your beaker when the liquid has been boiled off. 

Answer 2

Explanation:

It is known that the boiling point of pure water is $100^{o}C$. But when an impurity or a solute has been added into the water then there occurs an elevation in the boiling point of water.

As a result, addition of a solute into the water will lead to an increase in the boiling point of water.

For example, if common salt (NaCl) is added into water then it will completely dissolve in water leading to the formation of a cleat solution. But when we boil this solution then its boiling point will be greater than $100^{o}C$.

This will prove that it is a salt solution and not a colorless liquid.

Thus, we can conclude that by boiling the given colorless liquid we can determine whether it is a pure water or a salt solution.