Question

What is the decreasing order of basically of pri-, sec-, and tert- , ethyl amines and ${\text{N}}{{\text{H}}_{\text{3}}}$ ?
A.${\text{N}}{{\text{H}}_{\text{3}}}{\text{ > }}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{N}}{{\text{H}}_{\text{2}}}{\text{ > (}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{{\text{)}}_{\text{2}}}{\text{NH > (}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{{\text{)}}_{\text{3}}}{\text{N}}$
B.${{\text{(}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{)}}_3}{\text{N > (}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{{\text{)}}_2}{\text{NH > }}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{N}}{{\text{H}}_{\text{2}}} > {\text{N}}{{\text{H}}_{\text{3}}}$
C.${{\text{(}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{)}}_2}{\text{NH > }}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{N}}{{\text{H}}_{\text{2}}} > {{\text{(}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{)}}_3}{\text{N}} > {\text{N}}{{\text{H}}_{\text{3}}}$
D.${{\text{(}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{)}}_2}{\text{NH > }}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{N}}{{\text{H}}_{\text{2}}} > {\text{N}}{{\text{H}}_{\text{3}}}{\text{ > (}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{{\text{)}}_3}{\text{N}}$

Answer 1

Hint: The derivatives of carbon known as organic compounds are amines are one of them. Amines have one or more nitrogen atoms in them. According to the number of alkyl groups attached they are characterized as primary, secondary and tertiary amines.

Complete step by step answer:
The compounds composed of carbon and its derivatives are known as organic compounds. Amines are also organic compounds, they contain nitrogen atoms along with carbon and its derivatives. The number of nitrogen can be one more than one. Amines are characterized as primary, secondary and tertiary amines. When one hydrogen is replaced by the alkyl or aromatic group from the ammonia then it is known as primary amine, similarly when two hydrogen atoms are replaced then it is termed as secondary amines and when all the three hydrogen atoms are replaced by the alkyl or aromatic group then the ammonia becomes tertiary amine.
As we all know that alkyl groups are electron donating or electron releasing groups , the release electron due to +I effect which increases the availability of electrons on the nitrogen atom present in the given specific amine. Due to high availability of electrons on the nitrogen atom of amine it behaves as a base and as the number of alkyl groups increases in the amine structure the base keep on becoming stronger, hence we can say that the number if alkyl groups in an amine is directly proportional too its basicity.
Due to steric hindrance created by large alkyl groups there are some irregularities in the order; in case of ethyl as the alkyl group the order of basicity is as follows: ${\text{2}}^\circ {\text{amine > 1}}^\circ {\text{amine > 3}}^\circ {\text{amine > N}}{{\text{H}}_{\text{3}}}$

 ${{\text{(}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{)}}_2}{\text{NH > }}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{N}}{{\text{H}}_{\text{2}}} > {{\text{(}}{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}{\text{)}}_3}{\text{N}} > {\text{N}}{{\text{H}}_{\text{3}}}$

So, option (C) is correct.

Note: Amines have a great use in industries and industrial processes. Mostly the amines are used in the oil refineries, amines are used to remove the sour gases from the mixture of liquid hydrocarbons and liquid petroleum gases.