Question

Considering the basic strength of amines in aqueous solution, which one has the smallest $pK_b$ value?

• A. $(CH_3)_2NH$
• B. $CH_3NH_2$
• C. $(CH_3)_3 N$
• D. $C_6H_5NH_2$

Answer 1

Answer: (A)

$(CH_3)_2NH$

Answer 2

Among $C _{6} H _{5} NH _{2^{\prime}} CH _{3} NH _{2^{\prime}}\left( CH _{3}\right)_{2} NH$
$\left( CH _{3}\right)_{3} N \cdot C _{6} H _{5} NH _{2}$ is least basic due to resonance

Out of $\left( CH _{3}\right)_{3} N , CH _{3} NH _{2^{\prime}}\left( CH _{3}\right)_{2} NH \cdot\left( CH _{3}\right)_{2} NH$ is most basic due to +1 effect and hydrogen bonding in

$H _{2} O$