Q. Consider thiol anion $\left( RS^{\ominus} \right)$and alkoxy anion$\left( RS^{\ominus} \right)$. Which of the following statement is correct?
A) $RS^{\ominus}$ is less basic and less nucleophilic than $RO^{\ominus}$
B) $RS^{\ominus}$ is less basic but more nucleophilic than $RO^{\ominus}$
C) $RS^{\ominus}$ is less basic and more nucleophilic than $RO^{\ominus}$
D) $RS^{\ominus}$ is more basic but less nucleophilic than $RO^{\ominus}$
Explanation
(b)
Nucleophilic strength increases down a column of the Periodic Table (in solvents that can have hydrogen bonds, such as water, alcohols, thio alcohols).
Nucleophilic strength $RO^{-} < RS^{-}$
Base strength $RO^{\circleddash} > RS^{-}$
Thus, $RO^{\circleddash}$ is more nucleophilic but less basic than $RO^{-}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.