You have been provided with three test tubes. One of them contains distilled water and the other two contain 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(5m)
Answers
Solution!!
Distilled water is the purest form of water which is in one of the test tubes. The other two test tubes contain an acidic and a basic solution. We are only given red litmus paper. Tear the red litmus paper into three pieces and dip those pieces in each solution of the test tube.
In one of the cases, the colour of the red litmus paper will turn blue. That solution is the basic solution, as we know that it turns red litmus blue. The other two pieces of the red litmus paper will not change colour because distilled water doesn't change of the litmus paper and as it is already red litmus paper, the acidic solution also will not change the colour of the paper. But we have a blue litmus paper now.
Dip the blue litmus paper in the other test tube. If the blue litmus paper turns red, then the solution is acidic. If the blue litmus paper doesn't change the colour then it is dipped in distilled water.