Ionic equilibria

[kenhung123]

Can strong acids have strong bases conjugate?

[luken93]

I don't think so. Theoretically, if you use the knowledge of Ka and Kb values, if you have a high value for Ka, then it is a strong acid, meaning that the conjugate base, Kb, will be a very small value.

Also consider HCl. In water, it ionises ~100%, because the H+ and Cl- don't want to be together. Therefore, even if the Cl took back the proton, it would immediatly get rid of it again..

But knowing Chemistry, there could quite possibly be exceptions to this rule!

[Mao]

Can strong acids have strong bases conjugate?

Take the two equations:


HA +H2O <--> A- + H3O+
A- + H2O <--> HA + OH-

We then have ,

Thus,

Therefore, strong acids (large Ka) will produce very very weak conjugate bases (very very small Kb). Weak acids will produce comparatively weak conjugate bases. Very weak acids will produce moderately strong conjugate bases.