Question

What is an acid-base indicator? Name two naturally occurring indicators.

Answer 1

1. Acid-base Indicators- They are the substances that indicate whether an aqueous solution is acidic or basic. They show different colors in acidic and basic mediums.
2. Commonly used acid-base indicators- Litmus, phenolphthalein.
3. Naturally occurring indicators :

• Turmeric - It is yellow in acidic solutions and red in basic solutions.
• Red onion water- It is red in acidic solutions, violet in neutral solutions, and green in basic solutions.