Mechanism of Substitution Reactions — Prelims Questions

Which of the following alkyl halides would be most reactive towards S$_N$1 reaction?

Which of the following conditions would favor an S$_N$2 reaction for a primary alkyl halide?

When (R)-2-bromobutane reacts with sodium hydroxide in acetone, what is the major product and its stereochemistry?

Which of the following is the best leaving group?

Which of the following statements about S$_N$1 reactions is INCORRECT?

Which of the following nucleophiles would be most effective in an S$_N$2 reaction in a protic solvent?