Boojho took some grains of boiled rice in a test tube ‘A’, and Paheli took boiled and chewed rice in a test tube ‘B’. Both of them poured 1 – 2 drops of iodine solution into the test tube and observed the colour change. What colour change would they have observed? Give reasons for your answer.

Question

MyClass24 · Accepted Answer

Soln:
In test-tube A colour of iodine changes to blue-black because of the reaction of iodine with starch. In test-tube B colour will not change because salivary amylase acts on starch while chewing, reducing it to simpler sugars.