Universal indicator

type of pH indicator

A universal indicator is a test to measure the pH value of a liquid. The solution that is used has several chemical indicators in it. This means that the indicator is able to show different colours (and therefore pH value ranges). The drawback of this solution is that it cannot be used for titrations, which expect a well-defined change in color.

A roll of universal indicator, with a color scale on the cover
Common colors
pH range Description Colour
< 3 Strong Acid Red
3-6 Weak Acid Orange/Yellow
7 Neutral Green
8-11 Weak Base Blue
> 11 Strong Base Violet/Purple