Question

The strongest base among the following is :

• A. $C_6{H}_{5}N{H}_2$
• B. $(C_6{H}_5{)}_{2}NH$
• C. $N{H}_3$
• D. $(C_2{H}_5{)}_{2}NH$

Answer 1

Answer: (D)

$(C_2{H}_5{)}_{2}NH$

$\left(C_2{H}_5{)}_{2}NH\right(2^o$ amine) is the strongest base. Basic nature of amines is due to the presence of lone pair of electrons on nitrogen atom which is available for the bond formation with Lewis acid. Due to the $+I$ effect, $2^o$ amine is better base than $1^o$ amine and $N{H}_3.$ In case of aromatic amines, the lone pair on nitrogen atom involved in resonance, therefore, not available for bond formation, so aromatic amines are less basic.