What may be the simplest and most inexpensive way to know that the product is formed in the reaction given below? [Image]

What may be the simplest and most inexpensive way to know that the product is formed in the reaction given below?

Select an option to attempt

1. A
   Mass spectrometry
2. B
   Reverse Phase HPLC
3. C
   CD spectroscopy
4. D
   Change of color upon addition of alkali

Correct Answer: Option D

Explanation

Simplest detection method for phenol formation

:The reaction shown generates a phenol (hydroxybenzene derivative) as the product.Detection methods and their practical applicability:• Color change with alkali (e.g., FeCl₃ test): Phenols give a distinctive purple/violet colour with ferric chloride, or strong red/blue with NaOH and a diazonium salt. This test requires only a drop of reagent and is instantaneous.• Mass spectrometry: Very sensitive but expensive, requires specialised equipment.• Reverse Phase HPLC: Accurate and quantitative but requires expensive instrumentation and expertise.• CD spectroscopy: Measures optical activity; not ideal for simple product detection.The simplest and most inexpensive method is a colorimetric test with alkali/FeCl₃.Answer: Change of color upon addition of alkali (Option 4).