Introduction:
When turmeric powder is mixed with soap water, it undergoes a chemical reaction that causes a change in color. This transformation can be observed as the turmeric powder turns from its initial yellow color to a vibrant red shade. This phenomenon can be explained by the reaction between the components of turmeric and the soap water.

Explanation:
The change in color occurs due to a chemical reaction between the curcumin compound present in turmeric and the basic properties of soap water. Curcumin is a natural pigment responsible for the yellow color of turmeric. It is a pH indicator, meaning it can change color depending on the acidity or alkalinity of its surroundings.

1. Curcumin:
Curcumin exists in a yellow form in its neutral state. It is relatively stable and retains its yellow color under normal conditions. However, when it comes into contact with a basic solution like soap water, it undergoes a chemical change.

2. Soap water:
Soap water is typically alkaline in nature due to the presence of soap, which is a base. The alkalinity arises from the hydroxide ions (OH-) released by the soap when dissolved in water. These hydroxide ions are responsible for the change in color of the turmeric powder.

3. pH Indicators:
Curcumin acts as a pH indicator, meaning it changes color depending on the pH level of its surroundings. When exposed to an alkaline environment, curcumin molecules gain additional hydrogen ions (H+), resulting in a change in the electronic structure of the molecule. This alteration causes the absorption of different wavelengths of light, leading to the observed color change.

4. Red Color Formation:
When turmeric powder is mixed with soap water, the curcumin molecules react with the hydroxide ions present in the alkaline solution. This reaction causes the curcumin to lose some hydrogen ions, resulting in the formation of a new compound called curcumin red. Curcumin red absorbs light in the blue-green region of the spectrum and reflects light in the red region, giving the solution a red appearance.

Conclusion:
The change in color of turmeric powder to red when mixed with soap water can be attributed to the chemical reaction between curcumin and the alkaline properties of soap water. This reaction leads to the formation of curcumin red, which absorbs and reflects light differently, resulting in the observed color change.