Water has very high sur face tension because of the strong hydrogen bond, which prevents it from wetting materials with nonpolar surfaces, such as waxy leaves, umbrellas. The addition of detergent (or) soap can reduce the surface tension and increase the wettability of water Air Nonpolar tail oap or detergent molecule Polar head Wa Figure 8.16 Soap or detergent molecules align themseles at the surface of liquid water so that their nonpolar tails can escape the polarity of the water. This arrangement disrupts the waters surface tension.Water has very high surface tension because of the strong hydrogen bond, which prevents it from wetting materials with nonpolar surfaces, such as waxy leaves, umbrellas. The addition of detergent (or) soap can reduce the surface tension and increase the wettability of water