Advertisements
Advertisements
Question
Give a plausible explanation for the following:
Why are aliphatic amines stronger bases than aromatic amines?
Advertisements
Solution 1
Due to the −R effect of the benzene ring, the electrons on the N- atom are less available in the case of aromatic amines. Therefore, the electrons on the N-atom in aromatic amines cannot be donated easily. This explains why aliphatic amines are stronger bases than aromatic amines.
Solution 2
Aromatic amines are far less basic than ammonia and aliphatic amines because of the following reasons:
- Due to resonance in aniline and other aromatic amines, the lone pair of electrons on the nitrogen atom gets delocalised over the benzene ring and thus it is less easily available for protonation. Therefore, aromatic amines are weaker bases than ammonia and aliphatic amines.
- Aromatic amines are more stable than corresponding protonated ions; Hence, they have very little tendency to combine with a proton to form a corresponding protonated ion, and thus they are less basic.
APPEARS IN
RELATED QUESTIONS
Identify the weakest base amongst the following :
(a) p- methoxyaniline
(b) o-toluidine
(c) benzene - 1, 4 - diamine
(d) 4 - aminobenzoic acid
Give reason for the following:
Primary amines have higher boiling point than tertiary amines.
Arrange the following: C2H5NH2, C2H5OH, (CH3)3N – in the increasing order of their boiling point
Arrange the following in increasing order of their basic strength :
C6H5 – NH2, C6H5 – CH2 – NH2, C6H5 – NH – CH3
Arrange the following in increasing order of their basic strength :
How will you convert Benzene into N, N-dimethylaniline?
Write a short note on ammonolysis.
Accomplish the following conversion:
Benzene to m-bromophenol
Accomplish the following conversion:
Aniline to p-bromoaniline
Give reasons CH3NH2 is more basic than C6H5NH2.
Choose the most correct option.
Which one of the following compounds has the highest boiling point?
Tertiary amines have lowest boiling points because ________________
A compound Z with molecular formula \[\ce{C3H9N}\] reacts with \[\ce{C6H5SO2Cl}\] to give a solid, insoluble in alkali. Identify Z.
Dimerisation of carboxylic acids is due to
Which one of the following compounds will liberate CO2, when treated with NaHCO3?
Arrange the following in increasing order of their boiling point:
C2H5OH, C2H5NH2, (C2H5)3N
Arrange the decreasing boiling point.
\[\ce{CH3COOH, C2H5OH, CH3NH2, CH3OCH3}\]
Write short note on the following:
Ammonolysis
