Answer:
FeBr₃ and NaOH
Explanation:
In a double displacement reaction, the ionic species of both reactants are exchanged between each other, as follows:
That way the cation Fe⁺³ (originally bonded to OH⁻) is bonded to the anion Br⁻ instead, while Na⁺ bonds to OH⁻ (instead of Br⁻).