Strontium chloride has a flurite structure, which of the statement is true for the structure of strontium chloride ?

Options

A. the strontium ions are in a body-centered cubic arrangement
B. the strontium ions are in a face-centered cubic arrangement
C. each chloride ion is at the centre of a cube of 8 strontium ions
D. each strontium ion is at the center of a tetrahedron of 4 chloride ions

Answer

To determine the correct statement about the structure of strontium chloride (SrCl2), which has a fluorite structure, we can analyze the given options step-by-step.

### Step-by-Step Solution:

1. **Understanding the Structure of SrCl2**:
- Strontium chloride adopts a fluorite structure, which is characterized by a specific arrangement of cations (Sr²⁺) and anions (Cl⁻).

2. **Identifying the Cation Arrangement**:
- In the fluorite structure, the cations (Sr²⁺) are arranged in a face-centered cubic (FCC) lattice. This means that the strontium ions occupy the corners and the face centers of the cubic unit cell.

3. **Identifying the Anion Arrangement**:
- The anions (Cl⁻) occupy the tetrahedral voids in the FCC lattice. In a unit cell of SrCl2, there are 8 tetrahedral voids, and each tetrahedral void can accommodate one chloride ion.

4. **Evaluating the Given Statements**:
- **Option 1**: "The strontium ions are in a body-centered cubic arrangement."
- This is incorrect. The strontium ions are in a face-centered cubic arrangement, not body-centered.

- **Option 2**: "Strontium ions are in face-centered cubic arrangement."
- This is correct. The strontium ions do indeed occupy the FCC arrangement.

- **Option 3**: "Each chloride ion is at the center of a cube of 8 strontium ions."
- This is incorrect. In the FCC structure, there are 4 strontium ions per unit cell, not 8.

- **Option 4**: "Each strontium ion is at the center of a tetrahedron of 4 chloride ions."
- This is also incorrect. While strontium ions are surrounded by chloride ions, the tetrahedral arrangement does not correspond to 4 chloride ions for each strontium ion in the way stated.

5. **Conclusion**:
- The only true statement regarding the structure of strontium chloride is **Option 2**: "Strontium ions are in face-centered cubic arrangement."

### Final Answer:
The correct statement about the structure of strontium chloride is: **Strontium ions are in face-centered cubic arrangement.**