Question

The action of cleaning of oily dirt by soap depends on

Answer 1

The action of cleaning of oily dirt by soap is based on presence of hydrophilic end (i.e ionic part ) and hydrophobic end (i.e. hydrocarbon part).

Cleansing action depends upon the micelle formation​.
When soap is added in water, soap molecules form micelle ​in such a way that​ the hydrophobic part is in contact with oil or grease droplets​ and hydrophilic parts ​remain out of the droplets​ so that it can interact with water.
The oil droplet surrounded by hydrophobic chains​ is pulled in water and removed from ​the dirty cloths.​