[dokter]

I am studying for an exam and i wanted to know if someone know how to determine how strong an acid without knowing the pka only based on structure  these are the deductions i have made
If the hydrogen is attatched to the most Electronegative element ex: CO2H2 > COH3
Double bonds are more acidic then single bonds and multiple double bonds are stronger than single double bond
ex: H-C=(O)-CH2-C=(O)-OH () - this is on top > CH3-CH-(CH3)-C=(O)-OH

i think these deductions are correct but i am not too sure and if there are more plese post the more i know the better it will be

[movies]

I think the best way is to know a handful of benchmark pKas (e.g., HCl, HOAc, EtOH, t-BuOH, acetylene, dimethyl malonate, benzene, diisopropyl amine, butene, butane) and then extrapolate the pKa of other molecules by rationilizing relative to the ones that you know.  For example, if you know that the pKa of HOAc is 4.76, you could predict that the pKa of trichloroacetic acid would be lower, which it is (pKa ~0.63).

[Mitch]

look at our pka values page link is to the left