Question
What are indicators ? Name the three common acid- base indicators and give their colours in acidic and basic solutions.
✓
Answer
An indicator is a chemical substance that is used to identify whether a given substance is an acid or a base by a sharp change in its colour. The three most common acid-base indicators are litmus, methyl orange and phenolphthalein
| Indicator | Color change | ||
| Neutral | Acidic | Basic | |
| Litmus | Purple | Red | Blue |
| Methyl | Orange | Red | Yellow |
| Phenolphthalein | Colorless | Colorless | Pink |
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