Universal indicator

A universal indicator is a test to measure the pH value of a liquid. The solution used contains several chemical indicators. The indicator is able to show different colors, 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.

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

A roll of universal indicator, with a color scale on the cover.

Common colors

Related pages

• Titration
• Litmus paper