Properties of Acids

At ordinary temperatures, most pure acids are solids. Many, however, are liquids, and a few are gases. Some acids, such as prussic acid (hydrogen cyanide), are deadly poison.

When acids are dissolved in water in sufficiently high concentration they typically have the following properties:

1. They have a sour taste. (The term acid is derived from acidus, the Latin word for sour.)

2. They are corrosive.

3. They will turn blue litmus paper red.

4. They will dissolve many metals (for example, iron, tin, and zinc) and at the same time release hydrogen gas.

5. They will conduct an electric current, with the simultaneous liberation of hydrogen gas.

Acids will react with substances called bases (for example, sodium hydroxide) to form salts (such as sodium chloride, or table salt). A base is a substance that is capable of accepting hydrogen from another substance; thus it can be considered the opposite of an acid.