Question

When a few drops of iodine solution are added to rice water, the solution turns blue- black in colour. This indicates that rice water contains:
(a) fats
(b) complex proteins
(c) starch
(d) simple proteins

Answer 1

Answer:

starch

Explanation:

When iodine solution were added to rice water, the solution turned blue black because of the presence of starch. When iodine comes in contact with starch, it forms starch Iodide complex because iodine gets stuck in the beta coils in the structure of amylose of starch. The starch iodide complex gives blue-black colour.

Answer 2

Answer: c- starch  

Explanation: Amylose in starch is the main factor for colour formation as iodine comes in contact with beta coils structure of amylose and gives blue - black colour with iodine. Thus, the reaction of iodine with rice water indicates that rice water contains starch. So, the correct answer is option C– Starch.