While studying ionic equilibrium, I came across the term "Isohydric Solutions" which is defined as:
Solutions of electrolyte are said to be isohydric if the concentration of the common ion present in them is the same and on mixing such solutions, there occurs no change in the degree of dissociation of either of the electrolyte.
But as I understand from reading the statement, in the isohydric solutions, we have two solutions with a common ion whose concentration is the same in both the solutions.
So, when we mix the two solutions, the concentration of the common ion in the reaction quotient should increase (to be more precise, it should double) and then according to Le-Chatelier's principle, both the reactions will go backward which I think can only happen when there is a change in the dissociation constant of the 2 reactions (as equilibrium constant is constant for constant temperature).
So what exactly does the definition of isohydric solution mean?