Question

Assertion : In the iodometric titration starch is used as an indicator.
Reason : Starch is a polysaccharide.

• A. If both assertion and reason are true and reason is the correct explanation of the assertion
• B. If both assertion and reason are true but reason is not the correct explanation of the assertion
• C. If assertion is true, but reason is false
• D. Both assertion and reason are false statements

Answer 1

Answer: (B)

Starch solution gives a blue (purple) colour with a drop of iodine solution because it form a starch iodide complex which is purple in colour. When it is titrated its colour disappear. So it is used in iodometric titration as an indicator. Starch is a polysaccharide. So, both the statements are true but reason is not correct explanation of assertion.