$CH_3SH$ is more acidic.
Work Step by Step
- In the first compound $(CH_3SH)$, the conjugate base will have a Sulfide with the negative charge. - In the second compound $(CH_3OH)$, the conjugate base will have a Oxygen with the negative charge. Since they are in the same column, we need to compare their sizes: - $S$ is bigger than $O$, so the charge is better stabilized on the $S^-$. - Therefore, $CH_3SH$ is more acidic.