Name: Nomenclature of Cyanides and Isocyanides
Uploaded: 2019-07-19
Duration: 15 min 47 s
Description: In the naming of cyanide, the longest chain of carbon atoms containing the −CN group is selected as the parent chain. Let's see the video to know more.

Question

Give plausible explanation for the following:
Why are amines less acidic than alcohols of comparable molecular masses?

Accepted Answer

Amines undergo protonation to give amide ion.
$\underset{(Acid)}{R - {NH}_{2}} \to \underset{\begin{matrix} Amide ion \\ (Conjugate base) \end{matrix}}{R ‐ \bar{N} H^{}} + H^{+}$
Similarly, alcohol loses a proton to give alkoxide ion.
$\underset{\begin{matrix} Alcohol \\ (Acid) \end{matrix}}{R - OH} \to \underset{\begin{matrix} Alkoxide ion \\ (Conjugate base) \end{matrix}}{R - O^{-}} + H^{+}$
Acidic strength $\propto$ stability of conjugate base or anion

Stability of conjugate base or anion $\propto$ charge density on anion $\propto$ electronegativity of atom.
In an amide, ion, the negative charge is on the $N$ -atom, whereas, in an alkoxide ion, the negative charge is on the $O$ -atom. Since, $O$ is more electronegative than $N, O$ can accommodate the negative charge more easily than $N$ . As a result, the amide ion is less stable than the alkoxide ion i.e., the conjugate base, amide is less stable than alkoxide ion. Hence, amines are less acidic than alcohols of comparable molecular masses.

Give plausible explanation for the following:
Why are amines less acidic than alcohols of comparable molecular masses?

Important Questions on Organic Compounds Containing Nitrogen

Learn and Prepare for any exam you want !

Give plausible explanation for the following: Why are amines less acidic than alcohols of comparable molecular masses?

Important Questions on Organic Compounds Containing Nitrogen

Learn and Prepare for any exam you want !

Give plausible explanation for the following:
Why are amines less acidic than alcohols of comparable molecular masses?