Due to Frenkel defect, the density of the ionic solids

Options

A. The density of the crystal increases
B. The density of the crystal decreases
C. The density of the crystal remains unchanged
D. There is no relationship between density of a crystal and defect present in it.

Explanation

To solve the question regarding the effect of Frenkel defect on the density of ionic solids, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Frenkel Defect**:
- A Frenkel defect occurs when a cation (or anion) leaves its lattice site and occupies an interstitial site within the crystal structure. This creates a vacancy at the original lattice site.

2. **Analyzing Charge Neutrality**:
- In a Frenkel defect, although a cation has moved, it remains within the crystal lattice. Therefore, the overall charge balance of the solid remains unchanged. The total number of cations and anions in the crystal remains the same.

3. **Considering Density**:
- Density is defined as mass per unit volume. In the case of a Frenkel defect, while a cation moves from its lattice site to an interstitial site, no ions are lost from the crystal. Thus, the total mass of the ionic solid remains constant.
- Since the volume of the crystal does not change significantly due to the movement of the cation within the lattice, the density of the crystal remains unchanged.

4. **Conclusion**:
- Based on the above analysis, we can conclude that the density of the ionic solids remains unchanged due to the presence of a Frenkel defect.

### Final Answer:
The density of the crystal remains unchanged due to the Frenkel defect.

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