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 Indicators:
Indicators are chemical substances that exhibit a visible change, typically a color change, when introduced to acidic or basic solutions. Their function is to identify whether a substance is an acid or a base.

Step 2: Types of Indicators:
Indicators are categorized into two primary types:
- Natural Indicators: Sourced from nature, primarily plants. Examples include turmeric, litmus, and red cabbage extract.
- Synthetic Indicators: Artificially synthesized in laboratory settings. Phenolphthalein and methyl orange are common examples.

Step 3: Analyzing the Options:
The objective is to identify a pair of substances derived from natural sources that can determine the acidic or basic nature of a substance.

- Turmeric: A natural indicator derived from the turmeric plant. It retains its yellow color in acidic solutions but changes to reddish-brown in basic solutions.
- Litmus: Another natural indicator, extracted from lichens. It appears red in acidic solutions and blue in basic solutions.

Both turmeric and litmus are commonly employed in both laboratory and household settings for the identification of acids and bases, serving as exemplary natural indicators.

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

Turmeric and Litmus