>>12588712pKa is a generalized form of pH.
pH=-log[H30+] in the simplest terms. However to appropriately calculate the pH from just information on the molecules in solution you need the association constant which is based on a variety of factors.
The relationship between bond dissociation energy and pKa is basically
. Now this is more just calculating the overall energy of the reaction rather than just the dissociation energy. The dissociation energy just gives the particular piece of the puzzle related to how badly the atoms normally would want to be apart. The final approximation here is based on some idea gas law fuckery and temperature constraints. The full formula would require some decomposition into enthalpy and entropy considerations an gets messy very quickly after that.
