The reactions of a compound KX with fluorine, chlorine, bromine in three different reactions are given below :
`2KX + F_2 to 2KF +X_2`
`2KX + Cl_2 to 2KCl + X_2`
`2KX + Br_2 to 2KBr + X_2`
then KX is ______.

Explanation

To determine the identity of the compound KX based on the given reactions, we will analyze the displacement reactions involving fluorine (F2), chlorine (Cl2), and bromine (Br2).

### Step-by-Step Solution:

1. **Identify the Reactions**: The reactions provided are:
- \(2KX + F_2 \rightarrow 2KF + X_2\)
- \(2KX + Cl_2 \rightarrow 2KCl + X_2\)
- \(2KX + Br_2 \rightarrow 2KBr + X_2\)
...