Question

Which of the following compounds has the smell of bitter almonds?
(A) Aniline
(B) Benzonitrile
(C) Phenyl isocyanide
(D) Nitrobenzene

Answer 1

Hint: Different organic compounds smell differently, and these smells can be used for preliminary identification of these compounds. Some of the organic compounds are odourless, and hence they cannot be identified by their odour. However, certain compounds that have a strong characteristic smell can be identified.

Complete Step by Step Solution:
Nitrobenzene, also known as nitrobenzol oil of mirbane, is an organic compound with the chemical formula${{C}_{6}}{{H}_{5}}N{{O}_{2}}$ . It is a very toxic, flammable, light-yellow, liquid aromatic organic compound. It is prepared by the reaction of benzene with conc.${{H}_{2}}S{{O}_{4}}$ , conc. $HN{{O}_{3}}$ and water. It has a large number of applications.

It is used in rubber chemicals, floor polish, shoe polish, insecticides, dyes, pharmaceuticals, paint solvents, etc. It is often used as a solvent in the lab, mainly for electrophilic reagents. As an electron withdrawing group, $-N{{O}_{2}}$ is present, so the acidity of the molecule increases as the positive charge on benzene increases. Hence, nitrobenzene is acidic in nature. It has the smell of bitter almonds.
Correct Option: (D) Nitrobenzene.

Additional Information: Nitrobenzene is a highly toxic substance. It can cause many problems, like kidney damage, headaches, nausea, and lung irritation. It may be fatal in some cases.

Note: The other compounds in the option have different smells, like aniline, which has a fishy smell; benzonitrile has an almond-like odour; and phenyl isocyanide has a very powerful, foul, and unbearable smell.