MHT CET 202624 AprilEvening Shift
- Exam
- MHT CET
- Year
- 2026
- Date
- 24 April
- Shift
- Evening Shift
- Subject
- Chemistry
- Chapter
- Amines
MHT CET 2026 · 24 April · Evening Shift · Chemistry · Amines
Which is the correct decreasing order of boiling point for...
Which is the correct decreasing order of boiling point for following amines?
Tertiary amine (I), Secondary amine (II), Primary amine (III)
Tertiary amine (I), Secondary amine (II), Primary amine (III)
Options
- A(I) > (II) > (III)
- B(III) > (I) > (II)
- C(II) > (I) > (III)
- D(III) > (II) > (I)
Correct answer
D. (III) > (II) > (I)
Step-by-step solution
Primary amines (III) have two hydrogen atoms attached to the nitrogen atom, allowing them to form extensive intermolecular hydrogen bonds.
Secondary amines (II) have only one hydrogen atom attached to the nitrogen atom, resulting in less extensive intermolecular hydrogen bonding compared to primary amines.
Tertiary amines (I) have no hydrogen atoms attached to the nitrogen atom, so they cannot form intermolecular hydrogen bonds with each other.
Due to the decreasing extent of hydrogen bonding, the boiling points follow the order: Primary amine (III) > Secondary amine (II) > Tertiary amine (I).
Answer: (III) > (II) > (I)
Secondary amines (II) have only one hydrogen atom attached to the nitrogen atom, resulting in less extensive intermolecular hydrogen bonding compared to primary amines.
Tertiary amines (I) have no hydrogen atoms attached to the nitrogen atom, so they cannot form intermolecular hydrogen bonds with each other.
Due to the decreasing extent of hydrogen bonding, the boiling points follow the order: Primary amine (III) > Secondary amine (II) > Tertiary amine (I).
Answer: (III) > (II) > (I)