Which chlorine compound produces the least detectable taste and odor?

Monochloramine is recognized for producing the least detectable taste and odor among the chlorine compounds listed. This is primarily due to its chemical properties and the way it interacts with water.

Monochloramine is formed by reacting chlorine with ammonia. This compound tends to possess a milder taste and odor compared to the more commonly utilized forms of chlorine, such as chlorine gas or chlorinated water. Chlorine gas is known for its strong and sometimes unpleasant smell, which can be easily detected even at low concentrations. Chlorinated water can also have a noticeable chlorine taste, especially when residual levels are high.

In contrast, monochloramine is often used for disinfection in drinking water systems because it not only effectively kills bacteria and viruses, but also forms fewer byproducts that can contribute to taste and odor issues in the finished water. Its stability and slower reaction rate also mean that it provides a longer-lasting residual in the water distribution system, which improves water quality without introducing noticeable flavors over time.

Therefore, the reason monochloramine is the correct answer is its ability to serve as a disinfectant while minimizing the sensory impacts that can occur with other chlorine compounds.