Question

how does the spot of turmeric on the cloth change its colour when we try to wash with soap?​

Answer 1

Answer:

The stains turn red when such clothes are washed with soap. ... It is because turmeric contains an acid (tartaric acid), while the soap contains a base (sodium hydroxide). When an acid reacts with a base, neutralization reaction takes place and the stain becomes neutral. Therefore, due to this reaction the stain turns red.

Answer 2

The spot of turmeric on the cloth changes its colour to red when we try to wash with soap as turmeric being a natural indicator changes colour on reacting with the alkaline soap solution.

• Turmeric is a natural indicator which is yellow in colour. It changes colour separately in an acidic and basic medium.

• It remains yellow on reacting with acidic or neutral solutions, however, changes its colour to red on reacting with basic/alkaline solutions.

• Soap is formed by the process of saponification involving a strong base and fatty acids. It is therefore, alkaline in nature and thereby reacts with turmeric to change its colour.