n-Butylamine (I), diethylamine (II) and N, N-dimethylethylamine (III) have the same molar mass. The increasing order of their boiling point is

Question

n-Butylamine (I), diethylamine (II) and N, N-dimethylethylamine (III) have the same molar mass. The increasing order of their boiling point is (A)  III < II < I  (B)  I < II < III  (C)  II < III < I  (D)  II < I < III

Tardigrade Admin · Accepted Answer

The boiling points of amines depends upon their degree of association and the degree of association is further depends upon the extent of H-bonding. Since

1^{\circ}

amines have two,

2^{\circ}

amines have one while 3° amines have no hydrogen atoms linked to nitrogen, therefore among isomeric amines,

1^{\circ}

amines have the highest, while

3^{\circ}

amines have the lowest boiling point. Thus, the increasing order of boiling point is

N, N - d im e t h y l e t h y l amin e (III) C H_{3} N C H_{3} ∣ C H_{2} C H_{2}

d i e t h y l amin e (II) < C H_{3} C H_{2} N H C H_{2} - C H_{3}

n - b u t y l amin e (I) < C H_{3} C H_{2} C H_{2} C H_{2} N H_{2}

Q. n-Butylamine $(I)$ , diethylamine $(II)$ and $N, N$ -dimethylethylamine $(III)$ have the same molar mass. The increasing order of their boiling point is

$III < II < I$

$I < II < III$

$II < III < I$

$II < I < III$

$III < I < II$

Q. n-Butylamine (I), diethylamine (II) and N,N-dimethylethylamine (III) have the same molar mass. The increasing order of their boiling point is

III<II<I

I<II<III

II<III<I

II<I<III