[alexofordummies]

CH3-CH2-CH2-CH2-SH has a smaller pKa (10.7) than CH3-CH2-CH2-CH2-OH (16)

why? oxygen is significantly more electronegative than sulfur, so I'd imagine that it'd have an easier time releasing it's proton and holding on that negative charge - but it doesn't.

The only thing I see that would account for this would be sulfur's expanded octet. I guess sulfur has a lot more room to hold that electron pair, while oxygen is somewhat maxed out.

So question 1,
Am I on the right track? Can someone elaborate on the details of what's happening here.

As well,
I don't know much about expanded octets other than they're there because
the 3d sub shell allows for extra bonds.

Question 2,
What course teaches 3+ row elements, expanded octet, etc... As well, if I wanted to learn it on my own could I just mess around with hybridization and MO diagrams, or is there some specific theory that accounts for it?

[azmanam]

#1 Expanded octet has nothing to do with it.  Sulfur obeys the octet rule in this example.  Sulfur is huge compared to oxygen.  When deprotonated, the conjugate base has a lot of room for the electrons to spread out.  The electrons will not repel each other as much as on oxygen.  More stable conjugate base = stronger conjugate acid.

http://www.chem.ucalgary.ca/courses/351/Carey5th/Ch01/ch1-8.html

#2 inorganic chemistry.