When chlorine is passed through a sample of water, the pH of the water sample would be

When chlorine gas is passed through water, it reacts with water to form hydrochloric acid (HCl) and hypochlorous acid (HClO). Hypochlorous acid is a weak acid and can dissociate to form hydrogen ions (H+) and hypochlorite ions (ClO-). The formation of H+ ions in the water will increase the concentration of H+ ions, resulting in a decrease in pH. Therefore, the pH of the water sample will be less than 7 (i.e., acidic) when chlorine is passed through it. It is important to note that the pH of the water sample will depend on the amount of chlorine passed through it, the initial pH of the water, and other factors such as temperature and the presence of other chemicals.