Which acids are formed when chlorine reacts with water?

When chlorine reacts with water, it undergoes hydrolysis, leading to the formation of hypochlorous acid and hydrochloric acid. This reaction can be described by the following chemical equation:

Cl2 + H2O → HOCl + HCl

Hypochlorous acid (HOCl) is an important compound that has disinfectant properties, making it a key player in many water treatment processes. Hydrochloric acid (HCl) is a strong acid that can result from the interaction, representing the byproduct of chlorine's reaction with water.

The formation of hypochlorous acid is significant because it contributes to the disinfection of water, effectively killing bacteria and other pathogens. This property is vital in maintaining safe drinking water standards and ensuring public health.

Other choices do not correctly represent the direct reaction products from chlorine and water. Sodium hypochlorite is formed through a different process involving the reaction of chlorine with sodium hydroxide, and chloramines and trihalomethanes are products of reactions involving nitrogen compounds or organic materials, not solely from chlorine and water. Overall, the formation of hypochlorous and hydrochloric acids is the primary and direct outcome of chlorine’s reaction with water.