Question

Select a pair of natural indicator from the following :

• A. Litmus and methyl orange
• B. Turmeric and Litmus
• C. Phenolphthalein and methyl orange
• D. Methyl orange and Turmeric

Answer 1

The Correct Option is B

Step 1: Understanding the concept of indicators:
Indicators are chemical substances that show a visible change (usually a color change) when added to acidic or basic solutions. They help in determining whether a substance is an acid or a base.

Step 2: Types of indicators:
There are two main types of indicators:
- Natural indicators: These are obtained from natural sources such as plants. They include turmeric, litmus, red cabbage extract, etc.
- Synthetic indicators: These are artificially prepared in laboratories. Examples include phenolphthalein and methyl orange.

Step 3: Analyzing the given options:
We need to select a pair that includes substances obtained from nature and that can indicate the acidic or basic nature of a substance.

- Turmeric: A natural indicator obtained from the turmeric plant. It remains yellow in acidic solutions but turns reddish-brown in basic solutions.
- Litmus: Another natural indicator, extracted from lichens. It turns red in acidic solutions and blue in basic solutions.

Both turmeric and litmus are widely used in labs and households for identifying acids and bases and are excellent examples of natural indicators.

Step 4: Conclusion:
The correct pair of natural indicators is:

Turmeric and Litmus