Litmus Paper

Litmus is a natural indicator .

• It is a purple coloured dye which is extracted from a plant called Lichen .
• It is also available in paper form.
• When chemicals are added to it, it changes colour according to the nature of the substance .
• When the chemical is neutral , its colour remains unchanged (purple).
• When the chemical is acidic in nature, its colour changes to red.
• When the chemical is basic in nature, its colour changes to blue.