See image — Haloalkanes and Haloarenes Chemistry Question

💡 Solution & Explanation

Step 1 - Concept: SN1 (Substitution Nucleophilic Unimolecular) reactions proceed via a carbocation intermediate. The rate-determining step is the ionization of the substrate to form the carbocation, which is a unimolecular step. Key features of SN1 reactions must be identified. Step 2 - Evaluate each statement: Statement (1): 'Rearrangement is possible' - TRUE for SN1. Since a carbocation intermediate is formed, hydride or alkyl shifts (rearrangements) can occur to give a more stable carbocation. This IS correctly associated with SN1. Statement (2): 'Rate is affected by polarity of solvent' - TRUE for SN1. Polar protic solvents stabilize the carbocation intermediate and the leaving group through solvation, so solvent polarity does affect SN1 rate. This IS correctly associated with SN1. Statement (3): 'The strength of the nucleophile is important in determining rate' - FALSE for SN1. In SN1, the rate-determining step is the ionization of the substrate (unimolecular), which does not involve the nucleophile. Therefore, nucleophile strength does NOT affect the rate of an SN1 reaction. This is NOT correctly associated with SN1. Statement (4): 'The reactivity series is tertiary > secondary > primary' - TRUE for SN1. Tertiary carbocations are most stable, so tertiary substrates react fastest via SN1, followed by secondary, then primary (which rarely undergo SN1). This IS correctly associated with SN1. Statement (5): 'Proceeds with complete inversion of configuration' - FALSE for SN1. Since SN1 proceeds through a planar carbocation intermediate, nucleophilic attack can occur from both faces, leading to racemization (mixture of inversion and retention), not complete inversion. Complete inversion (Walden inversion) is characteristic of SN2, not SN1. This is NOT correctly associated with SN1. Step 3 - Conclusion: Statements 3 and 5 are NOT correctly associated with SN1 reactions. Step 4 - Match to options: Statements 3 and 5 correspond to option (a) 3, 5. Step 5 - Why other options fail: - (b) 5 only: Misses statement 3, which is also incorrect for SN1. - (c) 2, 3, 5: Statement 2 is actually correct for SN1 (solvent polarity does affect rate), so including 2 is wrong. - (d) 3 only: Misses statement 5, which is also incorrect for SN1. Therefore, the correct answer is A.