Final answer:
Soaps and detergents differ in their chemical composition, with detergents showing superior performance in hard water due to their ability to form water-soluble products, unlike soaps which form insoluble compounds.
Step-by-step explanation:
The difference between soaps and detergents lies primarily in their chemical composition and their behavior in water, particularly hard water. Soaps tend to form insoluble compounds with calcium and magnesium in hard water, which reduces their cleaning efficacy. On the other hand, detergents contain nonpolar hydrocarbon chains and a polar sulfonate or sulfate group, making them more soluble in hard water and preventing the formation of insoluble deposits.
Detergents tested in the laboratory likely demonstrated superior performance in both distilled water and hard water compared to soaps. Detergents form water-soluble products with hard water ions, which allows them to maintain their cleaning power. This makes detergents a better choice for areas with hard water.
Detergents, such as those containing alkylbenzene sulfonates, are preferred in domestic contexts like laundry and dishwashing because they remain effective in hard water and often include surfactants that reduce surface tension, enhancing their cleaning action.