Let's take $\ce{ZnSO4}$ salt solution in water for example. So the ions inside my solution will be $\ce{H+}$, $\ce{OH-}$, $\ce{Zn^2+}$ and $\ce{SO4^2-}$.
My questions are:
Is the ionic conductivity measured for the solution gives an idea of mobility of zinc ions and sulfate, or is it a result of all four ions combined?
When we change the salt concentration of zinc sulfate, do we change the ionic conductivity of zinc and sulfate ions only, or all four ions?
Also, any undergrad university level source to understand this concept will be helpful.