Question

1. Why surface tension of a liquid decreases due to presence of detergent ?​

Answer 1

Answer:

Detergents have two ends: one is polar and the other end is hydrophobic (water hating). The polar end of the detergent can bond with the polar water molecules, reducing the water's surface tension

Answer 2

Detergents are potassium or sodium salts of  long alkyl chains terminated with sulfonate groups.

• They are soluble in hard water. They contain surfactants,Surfactants or surfactants are compounds that reduce the surface tension between two liquids,a gas and a liquid or a liquid and a solid.
• Surface tension is the tension of the liquid surface film caused by the attraction of the surface layer particles by the liquid.
• These surfactants lower the surface tension of water and increase its ability to stick to objects.Water will stick to clothing and spread over a larger area than usual.
• Therefore the detergent affects the surface tension.They tend to reduce  surface tension.Surfactants in detergents play a very important role. On the one hand, it sticks to water molecules, and on the other hand,to dirt on dirty clothes.
• Surfactants act on the lubricant by diffusing the water and then attaching it to the lubricant and when that water is treated it removes all the dirt.