Which of the following reagents is the best choice to convert an alkyl bromide to an alcohol via an S$N_2$ mechanism?

Which of the following species is the least nucleophilic?

Which of the following species is most likely to react as a nucleophile rather than as a base?

Which of the following molecules is a negatively charged nucleophile?

Which of the following correctly ranks the nucleophilicity of the species $F_{-}$, ${\mathrm{Cl}}_{-}$, ${\mathrm{Br}}_{-}$, and $I_{-}$ in water from greatest to least?

In aqueous solution, rank the following species in order of increasing nucleophilicity: $F_{-}$, ${\mathrm{Cl}}_{-}$, ${\mathrm{Br}}_{-}$, $I_{-}$.

For each pair, predict the stronger nucleophile in the SN2 reaction (using an alcohol as the solvent). Explain your prediction.

e. (CH₃)₃N or (CH₃)₂O

f. CH₃COO^– or CF₃COO^–