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.
| 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 |