Chemical indicators such as methyl orange, bromothymol blue, phenolphthalein and litmus are often used to determine the acidic or basic nature of a substance. The indicators change colour over a pH range.
|
Indicator |
pH range |
Type of indicator |
Picture |
|
Methyl orange |
3.1 to 4.4 |
Acidic indicator |
|
|
Bromothymol blue |
6.0 to 7.6 |
Neutral indicator |
|
|
Phenolphthalein |
8.3 to 10.0 |
Basic indicator |
|
|
Litmus |
5 to 8 |
General indicator |
|
