Advertisements
Advertisements
प्रश्न
Arrange the following.
In decreasing order of the pKb values C2H5NH2, C6H5NHCH3, (C2H)2NH and CH3NH2.
Advertisements
उत्तर
Due to the delocalization of the lone pair of electrons of the N-atom over the benzene ring, C6H5NHCH3 is far less basic than C2H5NH2, (C6H5)2NH and CH3NH2. Among C2H5NH2 and (C2H5)NH, (C2H5)2NH is more basic than C2H5NH2 due to the greater +I effect of the two C2H5 groups and stabilization of its conjugate acid by H-bonding.
Compare to Ethyl and methyl group, C2H5 – group has a more +I effect than CH3 – group. Therefore methylamine is weak base than ethylamine. Combining all these facts the relative basic strength of these four amines decreases in order.
(C2H5)2NH > C2H5NH2 > CH3NH2 > C6H5NHCH3
Since a stronger base has a lower pKb value, therefore pKb values decrease in the reverse order.
C6H5NHCH3 > CH3NH2 > C2H5NH2 > (C2H5)2NH
APPEARS IN
संबंधित प्रश्न
Choose the most correct option.
Carbylamine test is given by ____________.
Choose the most correct option.
Identify ‘B’ in the following reactions
\[\ce{CH3 - C ≡ N ->[Na/C2H5OH] A ->[NaNO2/dilHCl]B}\]
Assertion: Acetamide on reaction with KOH and bromine gives acetic acid.
Reason: Bromine catalyses hydrolysis of acetamide.
The order of basic strength for methyl substituted amines in aqueous solution is ____________.
Arrange the following.
In increasing order of boiling point C6H5OH, (CH3)2NH, C2H5NH2.
Arrange the following.
Increasing order of basic strength C6H5NH2, C6H5N(CH3)2, (C2H5)2NH and CH3NH2.
How will you prepare propan-1-amine from propanamide?
The following amine can be classified as (C2H5)2NH:
The amine formed from an amide by mean of bromine and alkali has how many number of carbon atoms?
Name the distinguishing test for differentiating 1° amine from 2° and 3° amine.
