What occurs when chlorine is added to water and the reaction of chlorine with organic and inorganic materials stops?

When chlorine is added to water, it undergoes a series of reactions, including its interaction with various organic and inorganic materials present in the water. The process of chlorination serves a dual purpose: disinfecting the water to kill pathogens and reacting with these materials to form chlorinated compounds, some of which may require further treatment or could pose health risks.

When the reaction of chlorine with organic and inorganic materials ceases, it indicates that all available chlorine has been consumed in these reactions, meaning that the chlorine demand has been satisfied. At this point, any remaining chlorine in the water is available for disinfection purposes, ensuring that the water retains its ability to inhibit microbial growth during distribution.

Understanding this concept is crucial in water treatment processes. It helps operators determine when the water is adequately treated and safe for potable use. The other options imply various stages or outcomes related to water treatment but do not accurately reflect the specific outcome of chlorine's interaction being complete. For instance, simply becoming potable or ready for distribution does not directly correlate with the point at which chlorine demand has been met.