Question

if hibiscus,turmeric,rose petals are given to you,mention the use of the above investigating acids and bases in the school lab​

Answer 1

they are olfactory indicator , which helps us to distinguish if a substance is acid or base based on the smell produced.

Answer 2

Answer:

These are examples of natural acid-base indicators

They have pigments that change color depending on the pH (acidicity or basicity) of a solution.

They can be used to make natural indicators

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Explanation:

Natural acid-base indicators have pigments in them that turn colour depending on the pH of the solution they are placed in.

They all contain pigments in them that can either turn/or not turn colour when placed in an acidic pH or a basic pH

Depending on their individual colour change, they can be used to tell acids and bases apart.

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Here are few examples of natural indicators and their distinguishing colour change in acidic or basic solutions:

• Hibiscus turns a range of colours depending on the pH of the solution.

Hibiscus contains the anthocyanin pigment that will turn reddish in acidic solution while dark green in basic solutions

• Rose petals contains cyanin pigment which turns from red to blue in basic solutions
• Turmeric - turmeric turns yellow in acid solution, remains yellow in neutral solution and turns red in basic solutions.
• Red cabbages -these also contain the pigment anthocyanin which is red in acid solution, purple in neutral and green in basic solutions.
• Cherries, grapes and blackberries - all these turn red in acids and blue-violet in bases.
• Beets - basic solutions turn beet juice from red to purple

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This is how these natural occuring substance can be used as acid-base indicators. Depending on the known color change in different pH values, these indicators are used to tell neutral, basic and acid solutions apart.