I started with distilled water and continually added small amounts of detegent to the water. I took capillary height readings after each addition of soap. I continued until the capillary height remainded constant even when adding more soap.
The capillary height started at 16mm for distilled water, then gradually got lower until it stayed at 6mm.
The results supported my hypothesis and verified information that I read in a reference book which stated that the surface tension of a soap solution is approximately one third that of distilled water. In my experiment, the final capillary height of the soap solution was 37.5 percent of the capillary height of the distilled water.
This experiment is to measurd the affect of soap on the surface tension of distilled water
Science Fair Project done By Elizabeth M. Hatakeyama