Please solve the following question:
In an activity rama took some boiled rice in test tube A and some chewed boiled rice in test tube B. She found that, on chewing rice tasted sweet. In the next step she added a few drops of dilute iodine solution to A and B
a)In which test tube did Rama observe change in colour. Write the colour also
Ans)
b)What is the reason for change in colour?
Ans)
c)In one of the test tubes, no colour change is observed. Why?
Ans)
Dear Student
Rama observed that rice in test tube A turns blue black on addition of Iodine.
Whereas, rice in test tube B does not show any colour change upon addition of Iodine.
The rice in test tube A would turn blue-black in colour due to the presence of carbohydrates ( Iodine turns blue-black in presence of carbohydrates) whereas no colour change would be seen in test tube B ( which has properly chewed up rice mixed with our saliva) as the presence of salivary amylase present in our saliva has already started breaking down carbohydrates into simpler sugar, thus, showing no significant colour change upon addition of iodine.
Regards
Rama observed that rice in test tube A turns blue black on addition of Iodine.
Whereas, rice in test tube B does not show any colour change upon addition of Iodine.
The rice in test tube A would turn blue-black in colour due to the presence of carbohydrates ( Iodine turns blue-black in presence of carbohydrates) whereas no colour change would be seen in test tube B ( which has properly chewed up rice mixed with our saliva) as the presence of salivary amylase present in our saliva has already started breaking down carbohydrates into simpler sugar, thus, showing no significant colour change upon addition of iodine.
Regards