This is a pushing question. We discussed how phenols are typically more acidic than alcohols, even though they both contain the same hydroxyl functional group, because phenols possess an aromatic ring that delocalizes the negative charge after a proton is removed. Consider the below structures. Would you expect structure A to be more acidic or less acidic than structure B?

Question

This is a pushing question. We discussed how phenols are typically more acidic than alcohols, even though they both contain the same hydroxyl functional group, because phenols possess an aromatic ring that delocalizes the negative charge after a proton is removed. Consider the below structures. Would you expect structure A to be more acidic or less acidic than structure B?

A- B-
OH OH
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/\\ /\\
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\// \//
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H F

a. Structure A is more acidic than structure B because the electronegative fluorine on structure B spreads the negative charge more after deprotonation.
b. Structure A is less acidic than structure B because the electronegative fluorine on structure B spreads the negative charge less after deprotonation.
c. Structure A is less acidic than structure B because the electronegative fluorine on structure B spreads the negative charge more after deprotonation.
d. The two compounds have the same acidity.

Answer 1

I have a problem like this and dod not know how to do it either :/

Answer 2

To determine which structure is more acidic, we need to analyze the factors that influence acidity. In this case, we have a phenol (structure A) and an alcohol (structure B). Phenols are typically more acidic than alcohols because the phenol's aromatic ring can delocalize the negative charge that forms after deprotonation. This delocalization stabilizes the resulting phenoxide ion.

In structure A, the OH group is attached to an aromatic ring, allowing for the delocalization of the negative charge. On the other hand, structure B is a simple alcohol with an OH group attached to a non-aromatic ring.

Now, let's analyze the effect of the electronegative fluorine atom in structure B. The fluorine atom is more electronegative than hydrogen, which means it will attract the electron density towards itself. This results in a partial negative charge on the fluorine atom. Due to this partial negative charge, the fluorine atom can stabilize the resulting negative charge more effectively by accepting the electron density.

Therefore, the correct answer is:

c. Structure A is less acidic than structure B because the electronegative fluorine on structure B spreads the negative charge more after deprotonation.