acidity quesiton

[laczlacylaci]

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Increasing pKA=decreasing acidity. this tests the inductive effect.
The more electronegative the atom=the more it makes the overall compound want to donate a proton=strong acid. So the compound with the F will be most acidic. O is second most electronegative so 2 and Br is less electronegative than O. So F>O>B and least acidic C.

Applying this to HF, HBr, H2O, HI, H2S we would instead do:
HI>HBr>HF>H2S>H2O
Comparing down a group, the bigger the atom, the stronger the acid. (HI, HBr, HF)

Comparing across a period (HF and H2O), the more electronegative, the more acidic, correct?

 

[TheLongGame]

Yes, conceptually you are correct. For the purposes of the MCAT, stick to what you have.

In reality...
The correct order is

2-fluoropropanoic, 2-bromopropanoic, methoxyacetic, propanoic... This answer choice isn't available, but it is indeed correct.

The pKa of the above compounds in order:

2.68, 2.97, 3.54, 4.87