Question

People use a variety of methods to clean clothes. After adding soap, they 'beat' the clothes on a stone or scrub etc. with a brush or the mixture is agitated in a washing machine. Why is agitation necessary to clean clothes?(Is it to remove the micelles in colloid or because of scum?)

Answer 1

A soap molecule consists of two parts i.e. hydrophilic part which attaches to the water and hydrophobic part which attaches oil and dirt. When dirt is mixed into the soapy water the soap molecules arranged themselves into small clusters known as micelles. These micelle remain suspended as colloid. To remove these micelles and clean the clothes, they are beaten scrubbed and agitated.