Question about H acidity with regards to sp, sp2 and sp3

[dentprincess]

Hi,

So with my DAT coming up next week (yikes!), I'm trying to fill in all the gaps in my knowledge.

I'm a little confused about hydrogen acidity after having done a question on DAT Bootcamp in which the most acidic H on a compound was a H off a carbon on a triple bond (sp hybridized). After reading the explanation given, I got that:

H on sp hybridized carbons > H on sp2 > H on sp3 is terms of acidity because greater s character makes it more stable.
However, I read somewhere that vinylic H have a pka of 44...so I am very confused as to how H on sp2 could be more acidic than a H on sp3...Any help would be greatly appreciated.

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[Jay20155555]

http://www.masterorganicchemistry.com/2010/06/18/know-your-pkas/

sp3 carbons have a pka of 50 so it would be more acidic

 

[MavsFan1990]

^Higher the Pka, the lower the acidity

So sp would be the most acidic (based on that chart)

 

[dentprincess]

http://www.masterorganicchemistry.com/2010/06/18/know-your-pkas/

sp3 carbons have a pka of 50 so it would be more acidic

That is an amazing chart...Glad I'm looking at it before the DAT haha. Thanks!