Question

Define indicator.

Answer 1

Indicators - These are the chemicals that are used to determine the nature of the substance.

• They help us in deciding whether a given solution is acidic, basic, or neutral in nature.
• Some of the naturally occurring indicators are china rose petals, litmus, turmeric, etc.

Indicators used to test basic solutions -

• Litmus - It turns blue when exposed to a basic solution.
• Phenolphthalein - It turns pink in a basic solution.

Indicators used to test acidic solutions -

• Methyl orange - It turns red in an acidic solution.
• Litmus - It turns red when dipped in an acidic solution.

Indicators used to test neutral solutions -

• Litmus - It shows no change on blue or red litmus paper.
• Phenolphthalein- It remains colorless in the case of a neutral solution.