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 |