Question

You have been provided with three test tubes. One of them contains distilled water and the other two have an acidic solution and a basic solution respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?

Answer 1

Put the given red litmus paper in each of the three test tubes.The solution which turns the red litmus paper to blue is basic.

Now, put this blue litmus paper in the remaining two test tubes.The one which turns it red again is acidic.

The test tube which has no effect on either red or blue litmus paper is distilled water.

Or
DISTILLED WATER : The red litmus paper does not change the colour.

ACIDIC SOLUTION : Only one test tube is left then that's comman sense this is acidic.Cause even it does not change the color.

BASIC SOLUTION : Red litmus paper turns into blue.