Which reagent is most effective for detecting ammonia brine?

The Nessler reagent is a chemical reagent traditionally used for the qualitative analysis of ammonia. It works by forming a colored complex when it reacts with ammonia in solution, which can be visually observed, making it particularly effective for detecting low concentrations of ammonia.

In this context, its specificity and ability to form a distinct color change allows for clear detection, even in challenging matrices such as ammonia brine. This sensitivity helps in accurately identifying the presence of ammonia, which is critical in various applications, including environmental monitoring and industrial processes.

Other options do not provide the same level of specificity or visual clarity in detecting ammonia. For instance, potassium of lime is involved in a different chemical process, and while carbonate of soda can react with acids, it does not specifically indicate ammonia content. CO2 gas does not participate in the detection of ammonia and is irrelevant in this context. Thus, the choice of the Nessler reagent as the most effective reagent for detecting ammonia brine is well-founded due to its proven reliability and clear visualization of results.