Question

Which of the following statement(s) is/are correct?
I. Starch is almost insoluble in cold water but relatively more soluble in boiling water.
II. Starch solution gives blue colour with $I_2$ solution in cold.
III. Starch is a reducing sugar.
IV. Starch forms osazone.

• A. III and IV
• B. I and II
• C. II and III
• D. I and IV

Answer 1

Answer: (B)

I. Starch is a polysaccharide. It is almost insoluble in cold water but relatively more soluble in boiling water.
Thus, statement I is correct.
II. Starch solution gives blue colour with $I_2$ solution in cold. Amylose, a component of starch, gives this blue colour with iodine.
Thus statement II is correct.
III. Starch is non-reducing sugar as the aldehyde group is not free.
Hence, statement III is incorrect.
IV. Starch cannot form osazone as the aldehyde group is not free.
Hence, statement IV is incorrect.