Question

how would you confIRM that colourless liquids give to you is pure water?

Answer 1

you can confirm it by using indicators like methyl orange
phenolphthalin
ph paper
ph indicator solution

Answer 2

By finding the boiling point of a given colourless liquid. If the liquid boils at 100°C at atmospheric pressure, then it is pure water. This is because pure substances have fixed melting and boiling point.