Final answer:
To rank species in order of increasing nucleophilicity in acetone, we must consider the basicity and polarizability of the species. In acetone, the nucleophilicity order is methanol < methanethiol < methyl anion < amide ion.
Step-by-step explanation:
The question involves ranking species in order of increasing nucleophilicity in acetone. Nucleophilicity refers to the ability of a chemical species to donate an electron pair and form a new bond. Specifically, we need to consider solvent effects since the solvent in this case is acetone, a polar aprotic solvent. In polar aprotic solvents, nucleophilicity correlates with the basicity of the nucleophile. Therefore, more basic species tend to be more nucleophilic.
- CH3SH: Methanethiol (or methyl mercaptan) is a thiol and can be a relatively good nucleophile due to the presence of sulfur, which is less electronegative than oxygen and more polarizable.
- CH3OH: Methanol is a weak nucleophile due to the electronegative oxygen holding onto its electrons tightly.
- CH3: The methyl anion is a strong nucleophile because of its full negative charge making it very reactive.
- NH2-: The amide ion is an extremely strong nucleophile due to its negative charge and nitrogen being less electronegative than oxygen.
Given these considerations, we can rank these species in order of increasing nucleophilicity in acetone as follows: CH3OH < CH3SH < CH3 < NH2-.