Question

Two test tubes contain different solutions and are labelled as A and B. The table below shows the observations made when red and blue litmus papers were dipped in these test tubes.
Analyse the table and determine the solution A and B.​

	Test tube A	Test tube B
Red litmus	No change	Turns blue
Blue litmus	Turns red	No change

• A. A - Acid, B - Base
• B. A - Base, B - Acid
• C. A - Neutral, B - Base
• D. A - Neutral, B - Acid

Answer 1

The correct option is A A - Acid, B - Base

• Litmus paper is used to identify the nature of a solution. It is available in two colours- red and blue:
• The following table shows the colour of each litmus paper in different medium:

	Acidic	Basic	Neutral
Blue litmus	Red	No change	No change
Red litmus	No change	Blue	No change

• When red litmus paper was put in both the test tubes A and B, it turned blue in test tube B and remained unaffected in A. So, it confirms the solution in test tube B is basic.​

• When blue litmus paper was put in both the test tubes, it turned red in A and remained same in test tube B. So, it confirms the solution in test tube A is acidic.​