What is the stronger base, OH^- or CH30^-?
I've been told the answer is the conjugate base of methanol ion but i beg to differ. THe respective pKa's of water and methanol (the conjugate acids) are 15.7 and 15.5. This would imply that out of water and methanol, methanol is the stronger acid and hence, its conjugate base would be weaker than the hydroxide ion, not stronger. please clarify.
I agree with you although I could not verify the 15.5 for pKa for CH3OH. I found 15.2; however, both 15.5 and 15.2 makes CH3OH a stronger acid than water at 15.7. I assume the 15+ quoted in these sources for CH3OH is in aqueous solution. The Ka may be different in non-aqueous solution.
To determine which base is stronger, we compare the stability of their conjugate acids. The stronger the conjugate acid, the weaker the conjugate base.
Here, you correctly pointed out that the pKa of methanol is 15.5, which is lower (more acidic) than the pKa of water, which is 15.7. This means that methanol is a slightly stronger acid than water.
Now let's understand the concept of pKa values. The larger the pKa value, the weaker the acid and stronger its conjugate base. So, in this case, water has a larger pKa value than methanol, indicating that water is a weaker acid and its conjugate base (OH-) is stronger than the conjugate base of methanol (CH3O-).
Hence, the hydroxide ion (OH-) is a stronger base compared to the methoxide ion (CH3O-).