Acids and Bases

Acids and Bases

Introduction and Definitions:

Acids and bases are encountered frequently both in chemistry and in everyday living. They have opposite properties and have the ability to cancel or neutralize each other. Acids and bases are carefully regulated in the body by the lungs, blood, and kidneys through equilibrium processes.

What are acids and bases?

Observational definitions:

Acids:	Bases:
Taste sour.	Taste bitter.
Give sharp stinging pain in a cut or wound.	Feels slippery
Turn blue litmus paper red.	Turn red litmus paper blue.
Turn phenolphthalein colorless.	Turn phenolphthalein pink.
React with metals to produce hydrogen gas.
React with carbonates or bicarbonates to produce carbon dioxide gas.

See the graphic on the left as a base is wiped over the paper which already has the indicator phenolphthalein on it. The drawing changes to pink.

From: http://www.elmhurst.edu/~chm/vchembook/180acidsbases.html