Learn

Saturday, 10 October

JEE Main 2025 · ChemistryNumerical answerNumerical valueEasyCalculation

JEE Main 7 April 2025, Shift 1, Chemistry Q75

Question 75 of 75 in this shift, Chemistry question 25 of 25, Section B.

Thyroxine, the hormone has given below structure The percentage of iodine in thyroxine is ______%. (nearest integer) (Given molar mass in g mol−1\mathrm{g\,mol^{-1}} C:12, H:1, O:16, N:14, I:127)

The figure, in words

Structure of thyroxine: two benzene rings linked by an ether oxygen; the left ring carries HO and two iodines (ortho to OH), the right ring carries two iodines ortho to the ether O and a side chain CH2-CH(NH2)-COOH.

Official answer

65

NTA final key.

Chapter
Biomolecules
Topic
No close match in our taxonomy
Idea tested
No close match in our taxonomy

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.