Advertisements
Advertisements
Question
Give a plausible explanation for the following:
Why do primary amines have higher boiling points than tertiary amines?
Advertisements
Solution
In a molecule of tertiary amine, there are no H-atoms whereas in primary amines, two hydrogen atoms are present. Due to the presence of H-atoms, primary amines undergo extensive intermolecular H-bonding. As a result, extra energy is required to separate the molecules of primary amines. Hence, primary amines have higher boiling points than tertiary amines.
\[\begin{array}{cc}
\ce{H}\phantom{.............}\ce{H}\phantom{............}\ce{H}\phantom{....}\\
\phantom{...}|\phantom{..............}|\phantom{.............}|\phantom{.......}\\
\ce{\text{- - - - - -} N-H \text{- - - - - -} N-H \text{- - - - - -} N-H \text{- - - - - -}}\\
\phantom{...}|\phantom{..............}|\phantom{.............}|\phantom{.......}\\
\ce{\underset{Primary Amine}{R\phantom{.............}R\phantom{............}R\phantom{....}}}
\end{array}\]
\[\begin{array}{cc}
\ce{R}\phantom{....}\\
|\phantom{....}\\
\ce{N-R}\\
|\phantom{....}\\
\ce{\underset{Tertiary amine}{R}}\phantom{....}
\end{array}\]
APPEARS IN
RELATED QUESTIONS
How are 1 - nitropropane, 2-nitropropane and 2-methyl 2- nitropropane are distinguished from each other using nitrous acid?
What is the action of nitrous acid on tertiary nitroalkane
On heating an aliphatic primary amine with chloroform and ethanolic potassium hydroxide, the organic compound formed is ______.
Primary, secondary and tertiary amines may be separated by using ______.
Identify the compound that will react with Hinsberg’s reagent to give a solid which dissolves in alkali.
Arrange the following in the increasing order of their boiling points:
A: Butanamine
B: N, N-Dimethylethanamine
C: N- Etthylethanaminamine
Isocyanide reaction involves the intermediate formation of ______.
The presence of primary amines can be confirmed by ______.
Match List I with List II.
| List I | List II | ||
| (A) | Benzenesulphonyl chloride | (I) | Test for primary amines |
| (B) | Hoffmann bromamide reaction | (II) | Anti Saytzeff |
| (C) | Carbylamine reaction | (III) | Hinsberg reagent |
| (D) | Hoffmann orientation | (IV) | Known reaction of Isocyanates |
Choose the correct answer from the options given below:
A compound 'X' on treatment with Br2/NaOH, provided C3H9N, which gives positive carbylamine test. Compound 'X' is ______.
Give reasons:
(CH3)2NH is more basic than (CH3)3N in an aqueous solution.
In the reaction \[\ce{C6H5NH2 + CHCl3 + 3KOH -> A + 3B + 3C}\] the product A is:
Carbylamine test is the distinguishing test for ______.
Among dimethylamine (pKb = 3.27) and diethylamine (pKb = 3.0), which one is more basic?
Given below are certain cations. Using inorganic qualitative analysis, arrange them in increasing group number from 0 to VI.
- Al3+
- Cu2+
- Ba2+
- Co2+
- Mg2+
Choose the correct answer from the options given below:
