[wynn]

I was working on an acid base question and was confused how to determine the stability of a molecule when the negative charge is on the same molecule.
The correct answer: OH- is more stable
Can someone provide an explanation for me?

[Dan]

What is the difference between the two structures, and how might that difference affect the stability of the negative charge?

[Babcock_Hall]

Were you given the pKa of the conjugate acid of the alkoxide ion?

[wynn]

Were you given the pKa of the conjugate acid of the alkoxide ion?

I don't want to solve this problem using the pKa chart. Thank you anyway.

[wynn]

What is the difference between the two structures, and how might that difference affect the stability of the negative charge?

Is it because the oxygen in hydroxide draws a smaller amount of electron density toward itself from its neighboring atoms because the only atom attach to the oxygen is hydrogen?
I am not very sure.

[orgopete]

I resisted answering because the answer is paradoxical (or wrong).

Q: Why is carbocation stability mentioned in a separate chapter than electronegativity?
A: Is it to avoid students saying, "I thought carbon was more electron withdrawing than hydrogen?"

Obviously, if your textbook stated hydrogen is more electron withdrawing than carbon, this would be an easy question. Let's look at it differently. Tertiary butanol is the less acidic than methanol. What would you conclude about the electron withdrawing properties of carbon and hydrogen? Let me add more data, acetic acid (pKa 4.75) is less acidic than formic acid (pKa 3.75). You could look at the pKa's of substituted benzoic acids, phenols, anilines, the Hammett sigma values, etc. If you did, you would conclude carbon is a better electron donor than hydrogen. Let me repeat that hydrogen is more electron withdrawing than carbon.

My paper on explaining the energy differences that let to the electronegativity scale has been accepted to the Fall ACS Meeting in Philadelphia (link not available yet). Oh, and why electronegativity gives you the wrong answer.

[discodermolide]

My paper on explaining the energy differences that let to the electronegativity scale has been accepted to the Fall ACS Meeting in Philadelphia (link not available yet). Oh, and why electronegativity gives you the wrong answer.
[/quote]

Congratulations, can you post or sen me a copy please?

[wynn]

Here is conclusion I have after reading more sections about this topic from my text book. The reason that hydroxide is more stable is because it is less bulky, and therefore, it is further stabilized by the solvent. The author calls the solvating effect.

[orgopete]

If that is the point being made in your textbook, then that is a very plausible answer to this question. Hydrogen bonding can stabilize hydroxide as water has two bondable protons to contribute.

[Babcock_Hall]

If this is the correct explanation, then the gas phase basicities should be different from the solution basicities of the two bases in question.  It seems quite reasonable to me.