Like the litmus paper, turmeric is also a natural indicator. Turmeric solution turns red, when it comes in contact with bases. It is not affected by acids and neutral substances.

We will put a drop of each of hydrochloric acid; sodium hydroxide and sugar solution on turmeric indicator. The liquid which change the colour of turmeric indicator to red is basic in nature, that is, sodium hydroxide.

Now, we will pour a drop of sodium hydroxide in other two liquids separately. Then, we will put the drops of these liquids on turmeric indicator. The liquid which will not change the colour of turmeric indicator contains hydrochloric acid because sodium hydroxide neutralize the acid and forms a neutral solution. Whereas the liquid which change the colour of turmeric indicator to red is sugar solution. This is because the mixture of base and neutral solution is basic in nature.