Chapter 21, Problem 34P

Interpretation Introduction

Interpretation:

The quaternary ammonium salt should be identified.

Concept Introduction:

Surfactants are surface active agents. They are used to clean household items, clothes and many other things.

Surfactants contain a hydrophilic (water loving) part such as acid anions and a hydrophobic (water hating) part like alkyl chains.

Surfactants work by breaking the interface between water and oil or grease. The hydrophilic part is surrounded by water molecules while the hydrophobic part is surrounded by oil molecules.

Based on the nature of hydrophilic part, surfactants are classified into three parts:

• Anionic surfactants
• Cationic surfactants
• Zwitterionic or amphoteric surfactants

Anionic surfactants have negatively charged hydrophilic group. Some anionic surfactants are:

• Alkyl benzene sulfonates.
• Alkyl sulfates
• Alky ether sulfates
• Soaps

Cationic surfactants have positively charged hydrophilic group. Example − quaternary ammonium salts.

Correct Answer:

Option (iii)