If you look at the substances, you could test by interchanging the metals and nonmetals of each other. With that being said, K will combine with Br, and Al will combine with F. So, the complete reaction would be:
AlBr₃ (l) + KF (l) → AlF₃ (l) + KBr (l)
They won't appear as ions because they are not in the aqueous state. Only strong electrolytes dissolved in water dissociate into ions.