| INDICATOR SOLUTION | COLOUR CHANGE | PH RANGE |
| CONGO RED | VIOLET – ORANGE | 3.0 – 5.2 |
| PHENOLPHTHALEIN | COLOUR LESS – RED | 8.3 – 10.0 |
| UNIVERSAL PH | 5 – 7.5 | 4.0 – 11.0 |
| INDICATOR SOLUTION | COLOUR CHANGE | PH RANGE |
| CONGO RED | VIOLET – ORANGE | 3.0 – 5.2 |
| PHENOLPHTHALEIN | COLOUR LESS – RED | 8.3 – 10.0 |
| UNIVERSAL PH | 5 – 7.5 | 4.0 – 11.0 |
