7. Dorji has a few bottles of soft drinks in his restaurant. But, unfortunately, these are not labeled. He has to serve the drinks on the demand of customers. One customer wants an acidic drink, another wants a basic and the third one wants a neutral drink. How will Dorji decide which drink is to be served to whom?
If Dorji has litmus paper or solution then with the help of that he can distinguish between them by putting one drop of each drink on litmus paper. If the colour of the litmus paper changes to blue, then it is a basic drink and if the colour of the litmus paper changes to red, then it is an acidic drink and if no change in colour then it is neutral.
Another method is he can distinguish between them by tasting the drinks. Drinks with a sour taste are acidic whereas drinks with a bitter taste are basic and neutral drinks will have no taste.