What is a stonger base among methanthiolm and methanol?

Answer 1

Between methanethiol and methanol (if both species remain PROTONATED), I think methanethiol is the better base (ie, it is easier to form CH3CH2SH2+ than to form CH3CH2OH2+) because the lone pairs on the O are closer to the nucleus (O is more electronegative than S), so the O lone pairs are less available to reach out and grab a proton (aka they are less basic).

Between the DEPROTONATED forms, methoxide (CH3CH2O-) is definitely more basic than methanethiolate (CH3CH2S-). ?Methanol has a higher pKa than methanethiol by about 5 pH units).

Answer 2

Methanethiol is a stronger base than methanol because methanethiol is more basic due to the presence of the sulfur atom, which can donate its lone pair of electrons more readily than the oxygen atom in methanol.