Which of the following statements reagarding interhalogen compound is a gas at 298K?

Options

A. `ICI`
B. `IBr`
C. `BrF_5`
D. `CIF`

Answer

To determine which interhalogen compound is a gas at 298 K, we will analyze the states of the given compounds.

### Step 1: Identify the Interhalogen Compounds
The interhalogen compounds mentioned are:
1. ICl (Iodine monochloride)
2. IBr (Iodine bromide)
3. BrF5 (Bromine pentafluoride)
4. ClF (Chlorine monofluoride)

### Step 2: Determine the Physical States at 298 K
- **ICl**: Iodine monochloride exists in two solid forms, alpha and beta, at room temperature (298 K).
- **IBr**: Iodine bromide is known to be a black solid at room temperature.
- **BrF5**: Bromine pentafluoride is a colorless liquid at 298 K.
- **ClF**: Chlorine monofluoride is a colorless gas at room temperature.

### Step 3: Conclusion
Among the compounds listed, ClF (Chlorine monofluoride) is the only one that is a gas at 298 K.

### Final Answer
The interhalogen compound that is a gas at 298 K is **ClF**.

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