The pH scale measures the concentration of hydrogen ions in a chemical or substance and classifies it as acidic or basic, also called alkaline. A pH level of 7 is neutral, such as water, while a pH level below 7 is acidic and above 7 is basic. With a pH level of 10, soap is an alkaline or base.
The acid mantle on the skin serves as a protective layer, but it also builds up dirt, oils and germs. The alkalinity of soap breaks down this acidity through a neutralization reaction which cleanses the skin.Learn more about Solutions & Mixtures