Question

How would you distinguish between the solutions of chlorine in water and hydrogen chloride in water?

Answer 1

Aqueous solution of chlorine (chlorinated water) is& yellow. But over time, especially when stored in the light, it gradually fades. The reason is that chlorine interacts with water, forming hydrochloric and hypochlorous acid:
Cl2 + H2O → HCl + HOCl.
Last unstable and gradually decomposes to HCl and& oxygen& O2.
Therefore, a solution of chlorine in the water gradually turns into hydrochloric acid(hydrogen chloride) solution which is colorless.