Chapter 2, Problem 2.60P

Interpretation Introduction

(a)

Interpretation:

Hydrophilic head group and hydrophobic tail in hexadecyltrimethylammonium chloride is to be identified.

Concept introduction:

Cationic detergents are the detergents in which the active part of the molecule is a positive ion (cation). Cationic detergents are usually quaternary ammonium salts.

The ionic group in a detergent is the hydrophilic head group, and the nonpolar part of the detergent is the hydrophobic tail group.

Interpretation Introduction

(b)

Interpretation:

Micelle that would form, if the compound was dissolved in water, is to be drawn.

Concept introduction:

Detergents are long-chain molecules that are ionic on one end and highly non-polar on the other end. Detergents are dissolved in water as micelles, in which, the ionic head group is arranged on the exterior, and the hydrocarbon (non-polar) tails are arranged on the interior.

Interpretation Introduction

(c)

Interpretation:

Intermolecular forces that are primarily responsible for the solubility of micelles in water is to be determined.

Concept introduction:

In a micelle, the nonpolar tails are on the inside of the sphere, where they can interact with one another via extensive induced dipole–induced dipole interactions, whereas the cationic groups, that is, positively charged head groups are on the outside, where they can form the greatest number of ion–dipole interactions with the surrounding water molecules.