Question

Arnav is provided with three kinds of liquid of them one is sodium hydroxide; another is hydrochloric acid and third is a sugar solution. How will he identify them when he have only turmeric indicator?

Answer 1

Take the three liquids in three different test tubes and add turmeric indicator into each of them. One of the liquids will turn red. This is sodium hydroxide (base). The other two liquids will turn yellow. Then divide the red coloured sodium hydroxide solution into two test tubes. Thus there will be four test tubes, two of yellow and two of red. In one of the red liquids, add one of the yellow liquids, drop by drop. Similarly, do the same with the other two liquids. On doing so, one of the yellow liquids will change the red colour of the sodium hydroxide solution to yellow. This liquid is hydrochloric acid. The other liquid, which does not change the colour of sodium hydroxide, is the sugar solution.