How do you calculate Ka2 from Ka1?

Question

My professor has a lot of questions where he would have equilibrium constant Ka1, but somehow there is a value for Ka2 even though there is no concentration for it.

Answer 1

I'm not sure without the context exactly what your teacher is referring to, but usually the format "K_a1" and K_a2" would be used for the successive dissociation of a polyprotic acid. K_a1 is the constant for H₂X ↔ HX^- + H⁺, and K_a2 is the constant for HX^- ↔ X^2- + H⁺. I hope that helps!