Question

What is the correct order of nucleophilicity in the following options?

• A. $(C{H}_3{)}_{3}C{O}^{-}>C{H}_3^{-}$
• B. $C{H}_3{S}^{-}>C{H}_{3}SH$
• C. $C{H}_{3}C{H}_{2}C{H}_2{O}^{-}<(C{H}_3{)}_{3}C{O}^{-}$
• D. $(C{H}_{3}C{H}_2{)}_{3}N>(C{H}_{3}C{H}_2{)}_{3}P$

Answer 1

The correct option is B $C{H}_3{S}^{-}>C{H}_{3}SH$

(a). Alkoxides are weaker $N{u}^{-}$ than carbanion because negative charge on oxygen is more stable than carbon.
(b). In general, a charged/anionic nucleophile​ is stronger than a neutral nucleophile.
(c). As steric hindrance increases, nucleophilicity decreases.
(d). As we go down the group, nucleophilicity increases due to decrease in electronegativity.

Hence, option (b) is the correct answer.