SN1 mechanism, rate, stereochemistry, rearrangement

29 questions on SN1 mechanism, rate, stereochemistry, rearrangement from the Organic Reaction Mechanisms III: Nucleophilic Substitution chapter: 5 NEET level, 12 JEE Main, 12 JEE Advanced. Each one opens with its answer and solution.

• The hydrolysis of (CH3)3C-Br in aqueous acetone follows the SN1 mechanism. Its rate law is NEET level
• Optically active (S)-3-chloro-3-methylhexane is hydrolysed in aqueous acetone by the SN1 mechanism. The 3-methylhexan-3-ol obtained is NEET level
• The SN1 solvolysis of (CH3)3C-Cl is fastest in which of these solvents? NEET level
• The carbocation intermediate formed in an SN1 reaction is best described as NEET level
• In aqueous acetone, (C6H5)2CH-Cl solvolyses by SN1. When some LiCl is added to the solution, the observed rate of solvolysis NEET level
• For the SN1 hydrolysis of (CH3)3C-Br in aqueous acetone, the concentration of the bromide is tripled and that of added OH- is quadrupled at constant temperature... JEE Main level
• 2-Bromo-3,3-dimethylbutane, CH3-CHBr-C(CH3)3, is heated in ethanol with no added base. The major substitution product is JEE Main level
• 2-Bromo-3-methylbutane, (CH3)2CH-CHBr-CH3, is warmed in water. The main alcohol obtained is JEE Main level
• (1-Methylcyclobutyl)methyl bromide is solvolysed in aqueous ethanol. Taking the carbocation pathway that ends at the tertiary cation, the principal alcohol form... JEE Main level
• 3-Chlorobut-1-ene and 1-chlorobut-2-ene are each hydrolysed in water under conditions where the SN1 pathway operates. Which statement is correct (constitutional... JEE Main level
• Optically pure (R)-1-chloro-1-phenylethane, C6H5-CH(CH3)-Cl, is solvolysed in aqueous acetone. The product C6H5-CH(CH3)-OH is found to contain 64% of the produc... JEE Main level
• Assertion (A): The rate of solvolysis of (CH3)3C-Cl is much larger in 50% aqueous ethanol than in absolute ethanol. Reason (R): The transition state of the rate... JEE Main level
• Tert-butyl chloride is solvolysed in aqueous acetone containing 0.10 M NaN3 (a good nucleophile). Which statement is correct? JEE Main level
• Match the carbocations in List I with the main stabilising factor in List II. List I: (P) (CH3)3C+; (Q) CH3-O-CH2+; (R) C6H5-CH2+; (S) CH2=CH-CH2+. List II: (1)... JEE Main level
• Neopentyl bromide, (CH3)3C-CH2-Br, is heated in ethanol with no added base. The principal substitution product is JEE Main level
• The hydrolysis of (CH3)3C-Br in aqueous acetone follows SN1 kinetics and has a half-life of 30 min when no base is added. When the reaction is repeated with 1.0... JEE Main level
• cis-1-Bromo-4-tert-butyl-1-methylcyclohexane (bromine and the tert-butyl group on the same face) is hydrolysed in aqueous acetone by SN1. The alcohol product is JEE Main level
• Optically pure (S)-3-chloro-3-methylhexane, CH3CH2CH2-C(CH3)(Cl)-CH2CH3, is solvolysed in aqueous acetone via ion pairs, and the 3-methylhexan-3-ol formed is 76... JEE Advanced level
• Optically pure (R)-2-bromo-3,3-dimethylpentane is heated in aqueous ethanol and the substitution proceeds through a free carbocation that undergoes a 1,2-methyl... JEE Advanced level
• 1-Cyclobutylethyl bromide, C4H7-CH(CH3)-Br, is hydrolysed in water, and the alcohol A formed (via ring expansion and then a hydride shift to the most stable cat... JEE Advanced level
• 3-Chlorobut-1-ene is solvolysed in water through a free allylic cation. Counting every stereoisomer that can in principle form (E/Z isomers and enantiomers coun... JEE Advanced level
• The solvolysis of (C6H5)2CH-Cl is described by RCl <=>[k_1][k_-1] R+ + Cl- followed by fast capture of R+ by solvent with rate constant k_2, so that k_obs = k_1... JEE Advanced level
• 2-Bromo-3-methylpentane (any mixture of its stereoisomers) is solvolysed in methanol. Consider only substitution products (methyl ethers) arising either from th... JEE Advanced level
• For the hydrolysis of (CH3)3C-Br in aqueous acetone containing NaOH, choose the correct statement(s). JEE Advanced level
• On heating in ethanol (no added base), which of the following bromides give a substitution product whose carbon skeleton or substituent position has changed thr... JEE Advanced level
• Which of the following statements about stereochemistry in the SN1 reaction of an optically active tertiary alkyl halide are correct? JEE Advanced level
• Which of the following carbocations can be converted into a more stable carbocation by a single 1,2-shift of H or CH3? JEE Advanced level
• Neopentyl bromide, (CH3)3C-CH2-Br, is heated in ethanol without added base. Choose the correct statement(s). JEE Advanced level
• The solvolysis of (C6H5)2CH-Cl in 85% aqueous acetone is carried out (i) with added LiCl and (ii) with added NaN3. Choose the correct statement(s). JEE Advanced level