See image — IUPAC and Nomenclature Chemistry Question

💡 Solution & Explanation

Concept: A secondary carbon is a carbon atom bonded to exactly two other carbon atoms. A secondary hydrogen is a hydrogen atom attached to a secondary carbon. Step 1: Identify the molecular structure. The skeletal structure shown is 2,3-dibromobutane: CH3-CH(Br)-CH(Br)-CH3. Step 2: Label each carbon: - C1: CH3 (terminal) — bonded to 1 carbon → primary carbon - C2: CH(Br) — bonded to C1 and C3 → bonded to 2 carbons → secondary carbon - C3: CH(Br) — bonded to C2 and C4 → bonded to 2 carbons → secondary carbon - C4: CH3 (terminal) — bonded to 1 carbon → primary carbon Step 3: Count secondary carbons. C2 and C3 are both secondary carbons → 2 secondary carbons. Step 4: Count secondary hydrogens. Each secondary carbon (C2 and C3) bears one hydrogen atom (since each also has one Br and two C bonds, leaving one bond for H). C2 has 1 H, C3 has 1 H → total secondary hydrogens = 1 + 1 = 2. Step 5: The answer is 2 secondary carbons and 2 secondary hydrogens → option (b) 2, 2. Why other options fail: - (a) 2, 3: Overcounts secondary hydrogens; C2 and C3 each have only 1 H, not more. - (c) 3, 3: Overcounts both; there are only 2 secondary carbons. - (d) 2, 0: Incorrectly states zero secondary hydrogens; each secondary carbon carries one H. Therefore, the correct answer is B.