Chapter 22.3, Problem 15R

To determine

To Compare: The composition of detergents and soaps.

Explanation of Solution

Introduction: Both soaps and detergents are cleaning products but differ in composition.

Soaps are salts, having a sodium or potassium salt of a carboxylic acid group (−COOH) at one end and a non-polar chain of carbon atoms at the other end. The non-polar end of the soap interacts with non-polar oils, dirt and readily removes them. Soaps have a tendency to form scum in hard water and thus loses its efficiency. Soaps are biodegradable in the environment.

Detergents are also salts, having long hydrocarbon chains, but contrary to soaps, they contain a salt of a sulphuric acid group. The detergents are soluble in hard water, therefore do not form scum in it. Detergents may remain in the environment for along hence contributing water pollution.

Conclusion:

Soaps are sodium or potassium salts of a carboxylic acid having a long hydrocarbon chain attached to it. Detergents are sodium or potassium salts, having long hydrocarbon chains, ending with a sulphuric acid group.