Question

Which of the following is an acidic-base indicator?

• A. Vinegar
• B. Lime water
• C. Turmeric
• D. Baking soda

Answer 1

The correct option is C

Turmeric

Explanation for correct option:

C. Turmeric

Acid-base indicator:

• Acid-base indicators are also known as pH indicators.
• They are substances that change their color with pH at ${25}^{\mathrm{o}}\mathrm{C}$.
• They are usually weak acid/base when dissolved in water and dissociate partially into ions.
• Examples of some natural acid-base indicators such as turmeric, red cabbage as well as China rose.
• When turmeric is added to a basic solution, it turns the yellow color into deep red color and retains its color in acidic solution.

Explanation for incorrect options:

A. Vinegar is acidic in nature.

B. Lime water is basic in nature.

D. Baking soda is basic in nature.

Hence, the correct option is C i.e. Turmeric.