Q. What happens to the surface tension of water when detergent is added to it?
Answer: decreases
Notes: In the solid and liquid phase, water molecules are bonded to each other by virtue of an interaction between hydrogen atoms on one molecule and the oxygen atom of another . the process is referred to as "hydrogen bonding". The result is a kind of "skin" on liquid water’s surface. When soaps and detergents are added to water, they weaken the strength of the skin by interfering with hydrogen bonding between water molecules because the polar end of the soap or detergent is also attracted to the water. The overall effect comes out as a reduction in surface tension of water.