What is the difference between the chemical composition of soaps anddetergents?State in brief the action of soaps in removing an oily spot from a shirt. Why aresoaps not considered suitable for washing when water is hard?
Answers
2)When soap is dissolved in water, its hydrophobic ends attach themselves to dirt and remove it from the cloth.
First, the molecules of soap arrange themselves in micelle formation and trap the dirt at the centre of the cluster.
These micelles remain suspended in water like particles in a colloidal solution.
The various micelles present in water do not come together to form a precipitate as each micelle repels the other because of the ion-ion repulsion.
Thus, the dust particles remain trapped in micelles (which remain suspended) and are easily rinsed away with water.
Hence, soap micelles (oil) remove dirt by dissolving
3)Hard water contains bicarbonates, chlorides and sulphates of calcium and magnesium which react with soap molecules forming insoluble precipitates called scum. Hence, strength of soap molecules are lost in the chemical reaction and they are not available for cleansing action.
