Question

glucose and starch are both carbohydrates. why does glucose produce a negative result when testing using iodine?
a. the iodine test is not sensitive enough to detect glucose.
b. the glucose solution is not concentrated enough.
c. iodine only tests for polysaccharides, and glucose is a monosaccharide.

Explanation:

Iodine - starch reaction is specific to polysaccharides. Glucose, a monosaccharide, doesn't react with iodine in the same way.

Answer:

C. Iodine only tests for polysaccharides, and glucose is a monosaccharide