Lesson: Detergents Chemistry

In this lesson, we will learn how to describe the structure of anionic detergents and explain how they remove stains from fabrics.

Lesson Plan

Students will be able to

identify aromatic sulfonate salts as anionic detergents,
describe the chemical composition and structure of anionic detergents as containing a head and tail group,
identify the hydrophobic and hydrophilic moieties of an anionic detergent,
describe how anionic detergents work to remove fatty/oily stains from fabrics,
recognize the process of stain removal using anionic detergents from diagrams/images.

Lesson Presentation

Lesson Video

Lesson Explainer

Lesson Worksheet

Q1:

As well as removing stains, what other effect can anionic detergent molecules, such as those of alkylbenzene sulfonates, have when added to stained items in water?

Q2:

The structures of two alkylbenzene sulfonates are shown below.

Why might structure B be preferred over structure A as a commercial detergent?

Q3:

The following image shows a cartoon structure of sodium 4-dodecylbenzene sulfonate.

What structural arrangement will these molecules initially form when placed into water?