What is the product formed when chlorine is combined with nitrogenous compounds?

When chlorine reacts with nitrogenous compounds, the primary product formed is chloramines. Chloramines are formed when chlorine reacts with ammonia, a common nitrogenous compound found in water systems. This reaction results in a group of compounds that can be useful as disinfectants in water treatment because they are more stable and provide longer-lasting residual disinfection compared to free chlorine.

Chloramines, specifically, are important in water treatment practices because they help to control the formation of harmful disinfection byproducts that can occur when chlorine interacts with organic matter. They also help maintain a residual in the distribution system, further preventing microbial growth in the water supply.

While other substances like nitrogen dioxide and chlorine dioxide may be related to chlorine reactions, they are not produced directly from the reaction between chlorine and nitrogenous compounds in the same manner as chloramines. Monochloramine is a specific type of chloramine, but the broader category covers various chloramine compounds formed in such reactions, making chloramines the most accurate answer to the question posed.