
→ Molecular formula of Thyroxine ⇒ C15H11O4NI4
→ Molecular mass of Thyroxine -
C→15×12=180H→11×1=11O→16×4=64 N→14×1=14I→127×4=508
→ Molecular mass of Thyroxine ⇒777
→% of Iodine =777508×100=65.38%
Nearest integer =65
JEE Main 2025 — Chemistry Organic Chemistry
Thyroxine, the hormone has given below structure

The percentage of iodine in thyroxine is ____ %. (nearest integer)
(Given molar mass in gmol−1C:12.H:1,O:16, N:14,I:127)
Held on 7 Apr 2025 · Verified 6 Jul 2026.
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