While eating food, you spill some curry on your white shirt. You immediately scrub it with soap. What happens to its yellow colour on scrubbing with soap? Why? What happens to this stain when the shirt is washed with plenty of water?
On scrubbing, its colour changes from yellow to reddish brown. It happens because soap is basic in nature and the colour of turmeric changes from yellow to reddish brown in basic medium. When the shirt is washed with plenty of water, the stain turns yellow again.