Question

Lower aliphatic amines are soluble in water while higher amines are essentially insoluble in water. (True/False)

Hint:

Whenever the horizontal distance (base) equals the vertical distance (height), the angle of elevation is always $45^\circ$.

Answer 1

Concept:
Solubility of organic compounds in water depends on their ability to form hydrogen bonds and the size of the hydrophobic hydrocarbon chain.
Explanation:

Amines contain a nitrogen atom with a lone pair of electrons.
This allows formation of hydrogen bonds with water molecules.
Lower aliphatic amines (e.g., methylamine, ethylamine) have small alkyl groups, so hydrogen bonding dominates → high solubility.
Higher Amines:

As the alkyl chain length increases, the non-polar hydrocarbon portion increases.
Hydrophobic effect reduces interaction with water.
Thus, higher amines become less soluble or insoluble.
Conclusion:
The statement is correct. \[ \boxed{\text{True}} \]