propyne acidity?

[Xtian]

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what makes propyne so acidic? Is the H adjacent to the triple bond considered alpha? ---because causing resonance. Is this then true for triple and double bonded carbon groups?

 

[DrTacoElf]

what makes propyne so acidic? Is the H adjacent to the triple bond considered alpha? ---because causing resonance. Is this then true for triple and double bonded carbon groups?

Yes it has to do with resonance.

 

[Optimism Smiles]

what makes propyne so acidic? Is the H adjacent to the triple bond considered alpha? ---because causing resonance. Is this then true for triple and double bonded carbon groups?

It has to do with increasing "s" character of the triple bond. The triple bond carbon is sp hybridized, meaning it has 50% s character and is more acidic. An alkane carbon is sp3 hybridized, so it only has 25% "s" character. Also think of a triple bond being stronger than a single bond, making the H's on it more acidic.