Titrations
Indicators are used in titration solutions to signal the completion of the acid-base reaction. Did you know that the indicators are generally clear, but as the solution of known concentration is added using a burette, the solution in question will change colors? Different indicators are used for different pH ranges. Take a moment to view the table that contains several different commonly use indicators.
Indicator |
End Point Color in the Presence of Acid |
End Point Color in the Presence of Base |
pH Range |
|---|---|---|---|
| Thymol Blue | Red | Yellow | 1.2-1.8 |
| Methyl Orange | Red | Yellow | 3.2-4.4 |
| Bromocresol Green | Yellow | Blue | 3.8-5.4 |
| Methyl Red | Yellow | Red | 4.8-6.0 |
| Bromothymol Blue | Yellow | Red | 6.8-8.4 |
| Thymol Blye | Yellow | Blue | 8.0-9.6 |
| Phenolphtalein | Colorless | Pink | 8.2-10.0 |