Question

How will you detect the presence of urea in milk?

• A. When adulterated milk is treated with HCl and Resorcinol powder and boiled in water, it will give a red color
• B. When adulterated milk is mixed with para-dimethyl amino benzaldehyde, it will become deep yellow colored
• C. When adulterated milk is treated with para-phenylenediamine hydrochloric acid, it will give a dark blue color
• D. When adulterated milk is treated with ferric chloride solution and concentrated sulfuric acid, violet color develops at the junction of two layers

Hint:

Use specific chemical tests to detect adulterants like urea in milk.

Answer 1

The Correct Option is B

To detect urea adulteration in milk, combine the sample with para-dimethyl amino benzaldehyde. A subsequent deep yellow coloration confirms the presence of urea, a common adulterant.