When few drops of concentrated trioxonitrate(V) acid is added to an unknown sample and waned an intense yellow colouration is observed. The likely functional group present in the sample is

A. NH3—C—C=O
B. CHO
C. CO
D. CNH2

Correct Answer:

Option A – NH3—C—C=O

Explanation

Xanthopreitic test for the presence of protein, when conc nitric acid is added to the drop, an intense yellow colouration is observed.

It contains all the functional group of protein which includes the amino, alkanol and the carboxylic group. Adding few drops of conc HNO3 to a protein, gives an intense yellow colouration. It is called Xanthopreitic test.