See image — Haloalkanes and Haloarenes Chemistry Question

💡 Solution & Explanation

Let us analyze each statement one by one: Statement (1): Bridgehead halides are inert towards both S_N1 and S_N2 reactions (till one of the ring size is eight member ring). - For S_N2: Bridgehead carbons are sterically inaccessible from the back side due to the rigid bicyclic framework, making backside attack impossible. Hence inert to S_N2. - For S_N1: Formation of a carbocation at a bridgehead position is disfavored by Bredt's rule (the carbocation cannot achieve planarity/overlap with adjacent bonds due to the ring constraint), unless one of the rings is large enough (eight-membered or larger) to relieve strain. Hence inert to S_N1 under normal ring sizes. - Statement (1) is CORRECT. Statement (2): The first step in both S_N1 and E_1 reactions is the same. - Both S_N1 and E_1 are unimolecular reactions. In both cases, the first (rate-determining) step is the ionization of the substrate to form a carbocation intermediate. The carbocation can then either be attacked by a nucleophile (S_N1) or lose a proton (E_1). - Statement (2) is CORRECT. Statement (3): S_N2 reactions proceed with total retention of configuration. - S_N2 reactions proceed via a backside attack (Walden inversion), which results in INVERSION of configuration (not retention). Retention of configuration is NOT the outcome of S_N2. - Statement (3) is INCORRECT. Statement (4): E_2 eliminations are favored by the use of a solvent of low polarity and high concentration of a strong base. - E_2 is a bimolecular elimination. High concentration of a strong base promotes E_2 (the base abstracts a beta-proton simultaneously with leaving group departure). Low polarity solvents favor elimination over substitution because polar solvents stabilize ions (favoring S_N1/S_N2), while less polar solvents favor the concerted E_2 pathway. - Statement (4) is CORRECT. Correct statements: 1, 2, and 4 → Answer choice (a). Why other options fail: - (b) 1 and 3: Statement 3 is wrong (S_N2 gives inversion, not retention). - (c) 2, 3 and 4: Statement 3 is wrong. - (d) 1, 2, 3 and 4: Statement 3 is wrong. Therefore, the correct answer is A.