Which reaction is faster (i) or (ii) and what | vedclass

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(B) Both reactions involve a primary alkyl halide $(CH_3CH_2CH_2Br)$ reacting with a strong nucleophile in a polar aprotic solvent $(DMF)$,which follo

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reaction $(ii)$,$S_{N}2$

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(B) Both reactions involve a primary alkyl halide $(CH_3CH_2CH_2Br)$ reacting with a strong nucleophile in a polar aprotic solvent $(DMF)$,which follows the $S_{N}2$ mechanism.In an $S_{N}2$ reaction,the rate depends on the nucleophilicity of the attacking species.$CH_3S^-$ is a better nucleophile than $CH_3O^-$ because sulfur is larger,more polarizable,and less solvated in polar aprotic solvents compared to oxygen.Therefore,reaction $(ii)$ is faster than reaction $(i)$ due to the higher nucleophilicity of the thiomethoxide ion $(CH_3S^-)$.

Which reaction is faster $(i)$ or $(ii)$ and what is the mechanism?
$(i) \ CH_3CH_2CH_2Br + CH_3ONa \xrightarrow{DMF} CH_3CH_2CH_2OCH_3 + Br^-$
$(ii) \ CH_3CH_2CH_2Br + CH_3SNa \xrightarrow{DMF} CH_3CH_2CH_2SCH_3 + Br^-$

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Which reaction is faster $(i)$ or $(ii)$ and what is the mechanism? $(i) \ CH_3CH_2CH_2Br + CH_3ONa \xrightarrow{DMF} CH_3CH_2CH_2OCH_3 + Br^-$$(ii) \ CH_3CH_2CH_2Br + CH_3SNa \xrightarrow{DMF} CH_3CH_2CH_2SCH_3 + Br^-$