The mechanism action of soap is the molecules of oil and soap which break by rubbing into small oil droplets in the water which are emulsified.
The small emulsified oil droplets are washed away by the water.
Also the soaps molecules form micelles and assist in dissolving dirt and grime in water which helps to clean our hands, clothes, dishes etc.
The cleansing action of both soaps and detergents results from their ability to lower the surface tension of water, to emulsify oil or grease and to hold them in a suspension in water.
This ability is due to the structure of soaps and detergents.
In water, a sodium soap dissolves to form soap anions and sodium cations.
Soap is made of pin-shaped molecules, each of which has a hydrophilic head — it readily bonds with water — and a hydrophobic tail, which shuns water and prefers to link up with oils and fats.
Soap is produced by a saponification or basic hydrolysis reaction of a fat or oil.
Currently, sodium carbonate or sodium hydroxide is used to neutralize the fatty acid and convert it to the salt.
The cleansing action of soap occurs because Oil and grease can be absorbed into the hydrophobic centers of soap micelles and get washed away.
The cleaning action of soap is due to soap lather, which reduce the interfacial tension and solubilises the oily dirt into the water by emulsification.
The major difference between soap and detergent is that soap is produced from natural ingredients such as vegetable oils and animal fats.
In contrast, detergent is made from synthetic sources (petroleum fractions).
Sodium Isethionate helps water cling to the dirt and oil on your skin, allowing it to be washed away.
It's considered a mild cleansing agent.
Sodium Stearate is another traditional soap ingredient that is derived from coconut and palm oils.
It is the sodium salt of stearic acid and acts as an emulsifier.
The hardness of water is due to the presence of calcium and magnesium salts.
Soaps react with these salts to form an insoluble precipitate in water; this reduces the effectiveness of soap.
Detergents do not form insoluble precipitates with the calcium and magnesium ions in hard water.