A boy has a few bottles of soft drink in his restaurant. But ,unfortunately, these are not labelled. He has to serve the drinks on the demand of customers. One customer wants acidic drink, another wants basic and the third one wants neutral drink. How will the boy decide it to be served to whom?

Explanation:

The boy with the help of litmus paper can easily decide it as follows:

(i) The drink that would turn a red litmus to blue would surely be basic in nature.

(ii) The drink that turns a blue litmus to red is be acidic in nature.

(iii) The drink that would not be affected by both red and blue litmus would is  neutral in nature.

The test can be done with help of phenolphthalein or the methyl orange these reagents also show different color in different medium.