**(A):** In iodometric titrations, starch solution is added only near the end point.
**(R):** At high concentrations of , starch forms a very stable blue complex which does not easily react with

Question

**(A):** In iodometric titrations, starch solution is added only near the end point.
**(R):** At high concentrations of $I_2$, starch forms a very stable blue complex which does not easily react with $Na_2S_2O_3$ to release $I^-$.

Prashant Kotian · Accepted Answer

Correct answer: A. **Assertion:** Starch is used as an indicator for iodine. Adding it too early results in a deep blue color that is slow to decolorize. [1], [2]
**Reason:** The starch-iodine complex is an adsorption complex. At high iodine concentrations, the "clumping" makes the titration sluggish and the end point less sharp. [2], [3]

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