Organic Compounds And Hydrogenation

Step 1: Count atoms from structure

Carbon (C) = 15 atoms
Hydrogen (H) = 11 atoms
Oxygen (O) = 4 atoms
Nitrogen (N) = 1 atom
Iodine (I) = 4 atoms

Step 2: Compute mass contribution

Step 3: Total molar mass of thyroxine

Step 4: Percentage of Iodine

Correct Answer: 65%

The compound 'X' absorbs 2 moles of hydrogen, indicating the presence of a triple bond that is converted into a single bond. Upon oxidation with KMnO₄ in an acidic medium, the products are shown as:

• CH₃–C(=O)–CH₃
• CH₃–C(=O)–OH
• CH₃–C(=O)–CH₂–C(=O)–OH

The reactions show cleavage and oxidation of the triple bond and substituents, leading to ketones and acids.

To find the total σ bonds in the resultant compound 'X', calculate as follows:

• CH₃–C(=O)–CH₃: 9 σ bonds
• CH₃–C(=O)–OH: 7 σ bonds
• CH₃–C(=O)–CH₂–C(=O)–OH: 11 σ bonds

Summing them gives the total σ bonds: 9 + 7 + 11 = 27

The total number of σ bonds in compound 'X' is 27, which is within the provided range (27,27).

Step 1: Understanding the Concept:
The stability of alkenes is primarily determined by the degree of substitution at the double bond. According to Saytzeff's rule and hyperconjugation, more substituted alkenes are generally more stable.
Step 2: Detailed Explanation:
Stability increases with the number of -hydrogens (hyperconjugative structures).
C. 2,3-Dimethylbut-2-ene: . It is tetra-substituted and has 12 -H. (Most stable).
A. 2-Methylbut-2-ene: . It is tri-substituted and has 9 -H.
B. cis-But-2-ene: . It is di-substituted and has 6 -H.
D. Prop-1-ene: . It is mono-substituted and has 3 -H. (Least stable).
Order: C >A >B >D.
Step 3: Final Answer:
The stability order is C >A >B >D.