We drink very mild acids in our carbonated and fruit drinks. Stomach acids are important to digest foods. Bases Bases are chemical compounds that have a caustic action on plant and animal tissue. A common base is sodium hydroxide NaOH . It is also called lye and is the grease-cutting material in early forms of soap.
Bases feel slippery to the skin, as can be experienced with soap.
Sometimes a substance that is a base is called an alkali or alkaline . Bases can often be identified by the OH term in the end of their chemical formula, as seen in sodium hydroxide NaOH and potassium hydroxide KOH . Just like with acids, there are a some exceptions to this rule. Some organic acids have formulae that make them look like bases. That simply makes water neutral.