acid forms carbocation?

[SamuelTesla]

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Can an acid make a carbocation?

There is a reaction in the kaplan book exam on page 981. It shows a reaction where phosphoric acid abstracts a proton from propene, which becomes a carbocation. This carbocation then participates in an electrophilic substitution reaction.

What I don't understand is how an acid can make a carbocation... I know bases can abstract an acidic hydrogen to make a carbanion...

the only way it could make sense is that the acid somehow abstracts the pi electron in the double bond of propene, without removing the hydrogen... thx in advance...

 

[Salient]

I don't have the book, but propene would be abstracting the proton from phosphoric acid, not the other way around.

Since one side of the double bond gets the proton and the formerly pi electrons, the other becomes a carbocation.

 

[orgohacks]

I don't have the book, but propene would be abstracting the proton from phosphoric acid, not the other way around.

Since one side of the double bond gets the proton and the formerly pi electrons, the other becomes a carbocation.

Exactly. Double bond attacks proton and forms carbocation. The carbon which is more substituted will bear the positive charge (Markovnikoff's rule in action)