[coolguy99]

why is Hydroxide a stronger base than methoxide? I thought the carbon group in methoxide would localize the negative charge on the oxygen, making it more basic than just hydroxide?

[g-bones]

the slight difference in pKa (0.2) might be due to the polarizability of the methyl group over the hydrogen.  while, in general, adding more carbons to an alcohol (ie tert-butanol and isopropanol) decreases the acidity of the hyrogens, the hydrogen on hydroxide cannot serve to disperse the negative charge over its electron cloud (seeing as its much smaller) as well as the methyl group (larger electron cloud)