Question

When we wash the turmeric stain from our shirt , it gives red colour why?

Answer 1

Turmeric contains tartaric acid. When we wash the turmeric stain with soap or detergent which is a base the stain turns red. When we wash toe stain with enough water then it goes away.

Answer 2

turmeric is commonly known as an indicator and in this case it proves.
tartaric acid which is an acid present in turmeric acid when reacts with soap,turns red due to the acid and soaps basic properties.
soap is a base so turmeric turns red when reacts with base.
it turns dark yellow in acid solution