Question 6
A bottle contains a dilute HCl solution a second bottle contains an aqueous solution of caustic soda and a third bottle contains an aqueous solution of NaCl. With the help of a blue litmus paper only, how would you identify the contents of the three bottles?
Answer
To identify the contents of the three bottles using a blue litmus paper only, the following steps can be followed:
- Take a blue litmus paper and dip it into the solution in the first bottle.
- If the solution in the first bottle is HCl, the blue litmus paper will turn red due to the acidic nature of HCl.
- Take another blue litmus paper and dip it into the solution in the second bottle.
- If the solution in the second bottle is an aqueous solution of caustic soda (NaOH), the blue litmus paper will turn blue due to the basic nature of NaOH.
- Take a third blue litmus paper and dip it into the solution in the third bottle.
- If the solution in the third bottle is an aqueous solution of NaCl, the blue litmus paper will remain blue as NaCl is a neutral salt and does not affect the pH of the solution.
Therefore, by using a blue litmus paper, we can identify the contents of the three bottles as follows: Bottle 1 contains HCl, bottle 2 contains an aqueous solution of caustic soda (NaOH), and bottle 3 contains an aqueous solution of NaCl.