Introduction
Acid
An acid is a substance that has a sour taste, is corrosive, and can cause color changes in plant dyes. Vinegar, for example, owes its taste to acetic acid. Acids change the color of blue litmus paper to red.
Base
A base, on the other hand, has bitter taste and slippery or slimy to the touch. Soaps, which are essentially basic, have this property. Bases also cause color changes in plant dyes, and change the color of red litmus paper to blue.
Neutralization of Acids and Bases
A useful property of acid is its ability to react with metals and other materials. Acids neutralize bases. Similarly, bases can neutralize acids.
In people, acid forms in the mouth and can cause tooth decay if the teeth are not cleaned regularly. The best way to avoid this is to refrain from eating a lot of food with sugar. Cleaning the teeth after eating sugary food can also help fight tooth decay because toothpaste contains a base, which neutralizes the acid.
The human skin secretes natural acids on its surface to inhibit the growth of bacteria. The stomach secretes hydrochloric acid to help break down food into simpler substances.
