Chlorine water on standing loses its color and forms:

Step-by-step solution

Chlorine water loses it's yellow color on standing in sunlight because it forms mixture of hypochlorous acid ( HOCl ) and hydrochloric acid HCl . C l 2 ( g ) Is soluble in H 2 O and form chlorine water, in presence of sunlight as C l 2 g + H 2 O → H C l + H O C l This is a disproportionation reaction., where chlorine changes it's oxidation state from zero in Cl 2 to -1 in HCl and +1 in HOCl . Hypochlorous acid formed in this reaction gives nascent oxygen which is responsible for bleaching action