# Is there an online database of acid and basic dissociation constants?

Is there an online database of acid and basic dissociation constants, all in one place, free to use?

• Is this possibly what you are looking for? => csun.edu/~hcchm003/321/Ka.pdf and www2.ucdsb.on.ca/tiss/stretton/database/equilibrium_acids.htm and genchem1.chem.okstate.edu/1314F13/Database/ABKs.pdf .... ?
– user2117
Nov 13 '13 at 15:48
• Here is a very large table of pKas, measured in DMSO which allows the determination of a much broader range of acidities than measurements in water. Note however that acidities in water are not necessarily the same as acidities in DMSO, as the latter is a polar non-protic solvent. For example, $\ce{H2O}$ is approximately $10^{15}$ times more acidic in water than in DMSO (and equivalently, $\ce{OH-}$ is approximately $10^{15}$ times more basic in DMSO than in water). Nov 14 '13 at 10:29
• To add to my comment above, I have since realized that the same site also has an extensive section for acidities measured in water, here. May 15 '15 at 11:13

The Evans' and Bordwell $pK_a$ tables provide an excellent source of data for water and DMSO based measurements, particularly for organic compounds.