Which halogen would be able to displace the other from a compound?

The ability of a halogen to displace another from a compound depends on their reactivity, which in turn is determined by their position in the Periodic Table.

Halogen reactivity decreases down the group in the Periodic Table. This means that a halogen can displace another halogen that is located below it in the Periodic Table from its compounds in solution.

For example, Chlorine (Cl), which is above Bromine (Br) and Iodine (I), can displace both Bromine and Iodine from their compounds. Similarly, Bromine can displace Iodine from its compounds, but not Chlorine.

So, the halogen that can displace the other from a compound is the one higher up in the Periodic Table.