Amines MCQs for NEET — Chemistry Questions with Answers

The reaction given in option o3 is not correct. Aryldiazonium salts react with hypophosphorous acid (H$_3$PO$_2$) to give the corresponding aryl compound (benzene in this case), not an aryl phosphate. The correct reaction is:

$$ ext{C}_6 ext{H}_5 ext{N}_2^+ ext{Cl}^- + ext{H}_3 ext{PO}_2 ightarrow ext{C}_6 ext{H}_6 + ext{N}_2 + ext{HCl} $$

Therefore, option o3 is the incorrect reaction.

$ 2C_2H_5NH_2 + 2Na \rightarrow 2C_2H_5 NHNa + H_2 $

$ R- NH_2 +HNO_2 \rightarrow R - OH + N_2 + H_2O $ Aliphatic amine Alcohol

The Wurtz reaction is a coupling reaction in organic chemistry, typically used for coupling two alkyl halides to form a longer alkane chain. It is not used for the synthesis or separation of amines. The other methods listed (Hinsberg, Carbylamine, and Hofmann methods) are specifically related to the synthesis or separation of amines.

Ethylamine reacts with $HNO_2$ to form an alcohol, but aniline reacts with $HNO_2$ to form a diazonium salt, not a hydroxy compound. Therefore, the statement 'Ethylamine and aniline both react with $HNO_2$ to give hydroxy compounds' is incorrect.

$ -NO_2 $ ,group is electron with drawing group.

The Gabriel phthalimide reaction is used for the preparation of primary aliphatic amines. In this reaction, phthalimide is reacted with an alkyl halide to form N-alkylphthalimide, which on hydrolysis gives a primary aliphatic amine.

Benzene diazonium chloride is the most versatile compound in the synthesis of aromatic compounds. It can undergo a variety of reactions such as substitution, coupling, and reduction, making it a key intermediate in the synthesis of many aromatic derivatives.

The sequence of reactions given involves the following steps: 1) Nitrobenzene is reduced by Sn/HCl to form aniline (A). 2) Aniline reacts with excess bromine to form 2, 4, 6-tribromoaniline (B). 3) 2, 4, 6-tribromoaniline is then diazotized with NaNO2/HCl to form 2, 4, 6-tribromo benzene diazonium chloride (C). 4) Finally, the diazonium compound is reduced by H3PO2/H2O to form 1, 3, 5-tribromobenzene (D).