Three liquids are given to you. One is hydrochloric acid, another is sodium hydroxide and the third is a sugar solution. How will you identify them? You have only turmeric indicator
Answer:
A turmeric indicator is a natural indicator which works as follows:
- It does not change its colour when acidic or neutral substances are tested.
- Its colour changes to bright red when basic substances are tested.
To test the substances,
We will put a drop each of hydrochloric acid, sodium hydroxide, and sugar solution on the turmeric indicator.
- The liquid which changes the colour of turmeric indicator to red is basic in nature, that is, sodium hydroxide .
- Hence sodium hydroxide is identified.
Now, we'll mix a drop of sodium hydroxide with a drop of the other two solutions and then perform the test again.
1.
- If the resultant turns the turmeric red , it is a basic solution.
- We know that, (Basic solution + Neutral solution) = Basic solution
- (Sodium hydroxide + sugar) = Basic solution
- Hence this mixture contains the sugar solution.
2.
- If the resultant does not change the colour of the turmeric paper at all,
- It is a neutral solution formed due to the neutralisation reaction between Sodium Hydroxide and Hydrochloric Acid
- (Sodium hydroxide + hydrochloric acid) = Neutral
- Hence this mixture would contain hydrochloric acid.