Which of the following 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 each of the given compounds: ICl, IBr, BrF5, and ClF.

### Step 1: Identify the nature of each interhalogen compound.

1. **ICL (Iodine monochloride)**:
- ICl is known to exist in two forms: alpha and beta. The alpha form is a ruby red solid, and the beta form is a brown-red solid.
- **Conclusion**: ICl is a solid at 298 K.

2. **IBR (Iodine monobromide)**:
- IBr is a black solid at room temperature.
- **Conclusion**: IBr is a solid at 298 K.

3. **BrF5 (Bromine pentafluoride)**:
- BrF5 is a colorless liquid at room temperature.
- **Conclusion**: BrF5 is a liquid at 298 K.

4. **CLF (Chlorine fluoride)**:
- ClF is a colorless gas at room temperature.
- **Conclusion**: ClF is a gas at 298 K.

### Step 2: Compare the states of the compounds at 298 K.

- ICl: Solid
- IBr: Solid
- BrF5: Liquid
- ClF: Gas

### Final Conclusion:
Among the given interhalogen compounds, **ClF (Chlorine fluoride)** is the only compound that is a gas at 298 K.

### Answer:
**ClF is the interhalogen compound that is a gas at 298 K.**

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