Question

To show that turmeric powder acts as an indicator, the colour of which changes while mixed with washing soda or lemon juice . Give introduction to the question​

Answer 1

Answer:

Objective

This topic gives an overview of;

Acids And Bases

Litmus: A Natural Dye

Turmeric :Natural Indicator

China Rose as Indicator

Acid Rain

Indicators

We use in our daily life a large number of substances such as lemon, tamarind, common salt ,sugar and vinegar. Many substances that you encounter in your daily life have different properties. One major difference between substances is whether they are acidic or basic.

Some of the substances like Lemon juice, Vinegar, Curd, Grapes ,Unripe mango, Sugar, Tamarind taste sour, some taste bitter,some taste sweet and some taste salty.

Acids And Bases

Curd, lemon juice, orange juice and vinegar taste sour. These substances taste sour because they contain acids. The chemical nature of such substances is acidic. The word acid comes from the Latin word acere which means sour. The acids in these substances are natural acids.

Baking soda does not taste sour it means, that it has no acids in it. It is bitter in taste. If you rub its solution between fingers, it feels soapy. Substances like these which are bitter in taste and feel soapy on touching are known as bases. The nature of such substances is said to be basic.

Special type of substances are used to test whether a substance is acidic or basic. These substances are known as indicators. The indicators change their colour when added to a solution containing an acidic or a basic substance. Turmeric, litmus, china rosepetals (Gudhal), etc., are some of the naturally occurring indicators.