What are indicators? What are they used for? Give some examples of naturally occurring indicators. [3 MARKS]
Description: 1 Mark
Use: 1 Mark
Examples: 1 Mark
Substances that exhibit a change of colour or odour when added to acidic, basic and neutral solutions are called indicators.
Visual indicators show different colours in presence of an acidic and a basic solution. Similarly, olfactory indicators exhibit different odour when added to acids or bases. Thus, they help us in deciding whether a given solution is acidic or basic in nature.
Some of the naturally occurring indicators are china rose petals, litmus, turmeric, etc.