pH (Potential Hydrogen) | Chemistry Review


pH is basically a measure of how many hydrogen ions are in a substance. pH is very important to many fields, such as biology, chemistry, medicine, food science, farming, and water treatment.

I’ve written up here on the board a pH scale ranging from numbers zero to 14, each indicating the amount of pH in a substance. There are pH’s that go higher than 14, but for practical purposes this is the largest pH scale we need.

Water has a pH of 7. Any substance with a pH larger than 7 is considered a base. Everything from 7 over to 14 is considered a base. Common bases that you probably know of are baking soda and bleach.

Any substance with a pH below 7 is considered an acid. Some of those that you may know of are lemon juice, tomato juice, and gastric acid. Water is kind of the middle bar on the pH scale, and anything to the right is a base, and anything to the left is an acid.



by Mometrix Test Preparation | Last Updated: February 15, 2019