Question

What are indicators? With the help of an activity show that turmeric acts as an indicator.

Answer 1

Indicators are substances that show a change in colour on coming into contact with acids or bases.
Prepare a turmeric paste by adding a few drops of water to turmeric powder. Now, take a piece of paper and dip it into the turmeric paste and allow it to dry in the sunlight. When the paper is completely dried up, add a drop of soap solution on to the paper and observe. The region containing the soap solution turns red, indicating the basic nature of the soap solution. Hence, turmeric acts as an indicator.