Question
Will post this in a bit
Which of the following compounds is the strongest acid? Justify your answer: (explain in terms of conjugate bases, Ka, pKa, resonance etc) |dw:1440612688955:dw|
To compare acidity of compounds we must look at ARIO A = most significant in comparing while O = least significant in comparing. A = atom R = resonance I = induction O = orbitals.
There's another way we could look at this and that's based off of the Ka/pKa. A strong acid will have a weak conjugate base; meaning that the conjugate base won't have as great of a tendency to want to grab a proton. strong acid Ka > Kb (Ka here not pKa) let's say if we pulled off a proton from heptane |dw:1440613137241:dw| we all agree that this would be hard to do, because for a number of reasons 1. that negative charge isn't stabilized, it's localized on that carbon, which makes it unstable, there aren't any nearby electronegative atoms that could help to delocalize the charge and make it more stable. 2. because of this instability, the Kb would be greater than the Ka so this means we would have virtually none of that compound deprotinated if there were a strong enough base to remove a proton. Out of the three this one would obviously be the least acidic, in fact you could argue that it wouldn't be acidic at all.
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