What happens when chloroform when reacts with nitric acid?

\(CCl_3NO_2\)

Chloroform \((CHCl_3)\) reacts with nitric acid \((HNO_3)\) to form chloropicrin \((CCl_3NO_2)\)[also called war gas or tear gas]. This reaction is a nucleophilic substitution reaction, in which the chlorine atom on the chloroform molecule is replaced by a nitro group \((NO_2)\).

The nitro group is a very electronegative group, and it makes the chloropicrin molecule very stable. Chloropicrin is a colorless liquid with a strong odor, and it is used as a tear gas.

The other options are incorrect. \(C_2H_5C(NO)_2SH\) is the formula for ethyl mercaptan, \(CCl_3CH_2OH\) is the formula for chloroform hydrate, and \(CCl_3NO_3\) is the formula for trichlonitromethane. These compounds are not formed when chloroform reacts with nitric acid.

Therefore, the correct answer is (3) \(CCl_3NO_2\).