Abstract

Acid – base systems are commonly expected to equilibrate on a timescale much faster than any other chemical reaction, so their composition can be deduced from the corresponding pKa or pKb values. In a pH-jump experiment done on a multi acid/base pair system, it was found that it takes tens of microseconds before an equilibrium is established. Within that time, the system is kinetically driven reaching surprising states far different from its final equilibrium, for example carboxylate groups were protonated in the presence of hydroxyl ions.