Hi Natasha,
I would say you should have an idea of the generalized solubility rules. Here is a helpful link:
https://chem.libretexts....s/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Equilibria/Solubilty/Solubility_Rules
I have seen it on the actual MCAT once before, where you were expected to know the solubility of the substance without additional prompts. But overall, I wouldn't stress too much about it.
Hope this helps!:)