This is a partner experiment. While one person is doing the experiment the other is writing the test report (minutes).

The hands should be washed with a given soap under three different conditions:

1. with aqua dest.
2. with hard water (conc. CaCl2-solution)
3. with acidic water (dil. vinegar)

Give a small amount of soap on the palms of Your hands. Allow Your partner to make the hands wet with water and distribute the soap on the palms. Then a bigger amount of the water is taken in order to wash the soap away.

What do You feel / observe?

Clean Your hands completely with tap water, dry them and repeat the experiment under different conditions.