Name the indicator which can give us an idea of how strong or weak an acid or base is.
Name the indicator which can give us an idea of how strong or weak an acid or base is.
Universal indicator like ph paper or ph solutions give us an idea of how strong or weak an acid or base is.
Now an indicator is a substance, which is used to determine the end point in a titration. In acid-base titrations, organic substance (weak acids or weak bases) are generally used as indicators. They change their colour within a certain pH range. The colour change and the pH range of some common indicators are tabulated below:-
Table : Colour changes of indicators with pH
Indicator
pH range
Colour
Acid solution
Base solution
Methyl yellow
2.9 – 4.0
Red
Yellow
Methyl orange
3.1 – 4.4
Pink
Yellow
Methyl red
4.2 – 6.3
Red
Yellow
Litmus
5.0 – 8.0
Red
Blue
Phenolphthalein
8.3 – 10.0
Colourless
Pink
Universal indicator like ph paper or ph solutions give us an idea of how strong or weak an acid or base is.
Now an indicator is a substance, which is used to determine the end point in a titration. In acid-base titrations, organic substance (weak acids or weak bases) are generally used as indicators. They change their colour within a certain pH range. The colour change and the pH range of some common indicators are tabulated below:-
Table : Colour changes of indicators with pH
| Indicator | pH range | Colour | |
| Acid solution | Base solution | ||
| Methyl yellow | 2.9 – 4.0 | Red | Yellow |
| Methyl orange | 3.1 – 4.4 | Pink | Yellow |
| Methyl red | 4.2 – 6.3 | Red | Yellow |
| Litmus | 5.0 – 8.0 | Red | Blue |
| Phenolphthalein | 8.3 – 10.0 | Colourless | Pink |
