See image — IUPAC and Nomenclature Chemistry Question

💡 Solution & Explanation

Step 1: Identify the structure. CH2=CH-CH=CH2 is a four-carbon chain with two double bonds. Step 2: Count the carbon atoms. There are 4 carbons total, so the parent chain is 'but-' (butane base). Step 3: Identify the positions of the double bonds. Numbering from either end, the double bonds are between C1-C2 and C3-C4, giving locants 1 and 3. Step 4: Apply IUPAC nomenclature rules. For a hydrocarbon with two double bonds, the suffix is '-diene'. The parent name drops the '-ane' ending and adds '-diene' with locants: buta-1,3-diene. Step 5: Evaluate the options. (a) Butane — incorrect, this is the saturated alkane with no double bonds. (b) Buta-1,3-diene — correct IUPAC name; 4-carbon chain with double bonds at positions 1 and 3. (c) Butane-1,3-diene — incorrect; IUPAC rules require dropping the terminal 'e' of the alkane name before adding '-diene', giving 'buta-' not 'butane-'. (d) none of these — incorrect, since option (b) is valid. Therefore, the correct answer is B.