Write a short note on detergents.

Detergents are the sodium salt of sulphonic acids. In detergents, sulphonate

(-SO₃Na⁺) functional group is attached to hydrocarbon chain. The cleansing effect of the detergent is more effective because Ca²⁺ and Mg²⁺ ions present in hard water do not give precipitates with ions which are in soluble form. They remain in the solution and so detergent is not used in more quantity. Hence the use of detergent has increased. There are two parts in the structure of detergent molecule. One part is long hydrocarbon chain is known as non-polar tail which attracts towards dirt or oily stain. While the other negatively charged part (-SO₃^-Na⁺) is known as head which attracts towards water molecules. Concentrated solution of detergent applied on dirt or oil stain then non-polar part is attracted by oily stain or dirt.

When polar part remains in water then it attracts towards water and the spherical structure is formed around stain is called micelle. The part on which detergent is applied is being dragged by water so that the water gets dirty and the surface becomes clean.