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What is pH?

What is pH?

Author: Nathan Lampson

This lesson will explain what pH means, and the difference between substances with a high pH vs a low pH.

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pH is the measure of the acidity or basicity of a solution.  Acidity and basicity influence the properties of a solution.  pH is measured with a system of measurement called the pH scale.  A substance that has a pH of 7 is considered neutral -- equally acidic and basic.  Substances with a pH greater than 7 are considered basic.  Substances with a pH less than 7 are considered acidic.


The characteristics of acids and bases:

Acids increase the H+ ion concentration in a solution.

Acids neutralize bases.

Bases increase the OH- ion concentration in a solution.

Bases neutralize acids.



Ammonia is a base because it has a pH of 12

Orange juice is an acid because it has a pH of 3

What is pH?