In NaCl there are ________ schottky pairs per `cm^(3)` at room temperature

Options

A. `10^(22)`
B. `10^(16)`
C. `10^(6)`
D. `10^(12)`

Answer

To determine the number of Schottky pairs in NaCl at room temperature, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Schottky Defects**: Schottky defects are a type of point defect in ionic solids, where an equal number of cations and anions are missing from the lattice, creating vacancies.

2. **Know the Structure of NaCl**: NaCl crystallizes in a face-centered cubic (FCC) lattice structure. Each unit cell contains 4 Na⁺ ions and 4 Cl⁻ ions.

3. **Estimate the Number of Vacancies**: At room temperature, ionic solids like NaCl exhibit a certain number of Schottky defects due to thermal energy.

4. **Use the Known Value**: It is a well-established fact that at room temperature, NaCl has approximately \(10^6\) Schottky pairs per cubic centimeter.

5. **Final Answer**: Therefore, the number of Schottky pairs in NaCl at room temperature is \(10^6\) pairs per cm³.

### Conclusion:
In NaCl, there are \(10^6\) Schottky pairs per cm³ at room temperature.

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