Exam

JEE Main

Year

2025

Date

7 April

Shift

Morning Shift

Subject

Chemistry

Chapter

Chemistry in Everyday Life

JEE Main 2025 · 7 April · Morning Shift · Chemistry · Chemistry in Everyday Life

Thyroxine, the hormone has given below structure The percentage of...

Thyroxine, the hormone has given below structure

The percentage of iodine in thyroxine is ____ $\%$. (nearest integer)
(Given molar mass in $\mathrm{g} \mathrm{mol}^{-1} \mathrm{C}: 12. \mathrm{H}: 1, \mathrm{O}: 16$, $\mathrm{N}: 14,$\mathrm{I}$: 127)$

Step-by-step solution

\rightarrow$Molecular formula of Thyroxine$\Rightarrow$\mathrm{C}_{15} \mathrm{H}_{11} \mathrm{O}_4 \mathrm{NI}_4$
\rightarrow$Molecular mass of Thyroxine -<br />$$\begin{aligned} & \mathrm{C} \rightarrow 15 \times 12=180 \\ & \mathrm{H} \rightarrow 11 \times 1=11 \\ & \mathrm{O} \rightarrow 16 \times 4=64 \\ & \mathrm{~N} \rightarrow 14 \times 1=14 \\ & \mathrm{I} \rightarrow 127 \times 4=508\end{aligned}$$<br />\rightarrow$ Molecular mass of Thyroxine $\Rightarrow 777$
$$\begin{aligned}& \rightarrow \% \text{\text{ of } Iodine }=\frac{508}{777} \times 100 \& =65.38 \%\end{aligned}$$
Nearest integer $=65$