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

The test tube containing distilled water will not bring any change in the colour of blue litmus paper. It turns blue to red when the same litmus paper dipped in the solution containing acidic solution and the third test tube will have no change or effect as it is basic solution