Is it possible to predict a double displacement reaction between two ions where the products remain in aqueous solution? I see how you can predict precipitation reactions if you know whether the product(s) is/are soluble, but that doesn't apply to all possible double displacement reactions.
If there is no precipitate, then there is nothing to drive the reaction. Both possible products would be soluble, and so there is no net reaction (it's just the reactant ions in solution).
Prediction, you say, is possible if you know the reactivity series like this for an elemtary level.