Nesslerization in ammonia measurement yields which color?

• A. Yellow
• B. Blue
• C. Green
• D. Red

Answer: (A)

Nesslerization detects ammonia by forming a colored complex with Nessler's reagent in alkaline solution. The reaction produces a yellow coloration, and the intensity of the yellow grows as ammonia concentration increases. Among the common color outcomes, yellow is the characteristic result for this reaction, so it best matches what you would observe in practice. Blue, green, or red do not arise from this Nessler reaction with ammonia.