What is pH?

pH describes the acidity or alkalinity of a solution. A low pH indicates acidic conditions, and a high pH indicates basic conditions.

pH is actually a measure of the amount of hydrogen ions in solution. In fact, some people think of pH as being the "power of hydrogen." A low pH has a lot of free hydrogen ions in the water, whereas a high pH has relatively few. Technically, pH is the negative logarithm of the free hydrogen activity in solution.

Why is pH Important?

pH is very important, and is used to monitor safe water conditions. Many animals cannot live below a pH of 5 or above a pH of 9. Once the normal pH range for a water has been established, a rise or fall in pH can indicate chemical pollution, or acid rain.

How is pH measured? pH Sensor Technology pH Science Lesson