Based on the reality of life, let’s talk about why oil stains cannot be washed away with water alone, but can be washed away with soapy water.

Because oil is not easily soluble in water, it will form an emulsion with water, so it is difficult to wash off. The molecules of soapy water are composed of a hydrophilic group and a lipophilic group. One side combines with water and the other side with oil. By combining, the oil and water can be taken away by the molecules of soapy water. Then rinse with water, and the soapy water molecules can be washed away with the oil stains, so soapy water can wash away the oil stains