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?

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Chapter 2

NCERT

Class 10

Science

Solutions

1. 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

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Question:

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?

Answer:

Red litmus paper is kept alternately in three test tubes. The solution which turns red litmus paper blue is an alkaline solution. Now put each end of blue litmus paper in the remaining two test tubes separately. The solution which turns blue litmus paper red is an acidic solution. If there is no effect on red and blue litmus paper, then the solution is distilled water.

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