Question

Iodometric titration involves

• A. Direct titration with iodine
• B. Indirect titration using iodine
• C. Acid–base reaction
• D. Precipitation reaction

Hint:

There are two closely named iodine-based titrations: iodimetry and iodometry. They sound alike but work differently, and the question is testing whether you can tell them apart.

Answer 1

The Correct Option is B

Concept:
There are two closely named iodine-based titrations: iodimetry and iodometry. They sound alike but work differently, and the question is testing whether you can tell them apart.

Step 1: In iodimetry (direct method), iodine itself is used directly as the titrant to oxidise the substance being analysed. Here you titrate directly with iodine.

Step 2: In iodometry (indirect method), iodine is not added directly. Instead, the analyte (an oxidising agent) is made to react with excess potassium iodide, which liberates an equivalent amount of iodine. This liberated iodine is then titrated against standard sodium thiosulphate. Because the iodine is generated in the reaction and measured indirectly, it is an indirect titration using iodine.

Step 3: So iodometric titration is the indirect one. It is a redox (oxidation–reduction) process, not an acid–base or precipitation reaction.

Answer: Option (2) — Indirect titration using iodine.