What reaction leads to the formation of chloramines?

The formation of chloramines occurs through a reaction between ammonia and chlorine. When chlorine is added to water that contains ammonia, it reacts to form chloramines, which are a group of chemical compounds that include mono-, di-, and tri-chloramines. This process is significant in water treatment, especially in maintaining disinfection while reducing the formation of potentially harmful disinfection by-products that can arise from the use of chlorine alone.

The presence of ammonia in the water is crucial because chlorine has a higher affinity for reacting with ammonia than with organic matter or other compounds found in the water. As a result, chloramines can serve as a more stable and longer-lasting disinfectant compared to free chlorine, making them valuable for maintaining water quality in distribution systems.

Understanding this reaction is important for water treatment professionals, as it highlights the balance between effective disinfection and the potential formation of compounds that might affect water taste, odor, or safety. Other options do not lead to the formation of chloramines, focusing instead on different types of chemical reactions unrelated to the formation of these compounds.