Question

Due to Frenkel defect, the density of ionic solids:
A. Decreases
B. Increases
C. Does not change
D. Change depends on crystal structure

Answer 1

Hint:A Frenkel defect also known as dislocation defect is actually a type of point defect found in crystalline solids which are named after its discoverer Yakov Frenkel. This Defect explains a defect found in the molecule where an atom or ion leaves its own lattice site vacant.

Complete Answer:
A Frenkel defect also known as dislocation defect is actually a type of point defect found in crystalline solids which are named after its discoverer Yakov Frenkel. The defect forms when an atom or any ion leaves its place in the lattice, making a vacancy, and becomes an interstitial by lodging.
 Because of the Frenkel defect, the density of ionic solids does not change. The Frenkel defect does not have any impact on the density of the solid as it involves the migration of the ions along with the crystal, hence having both the volume as well as mass.

Hence, Option C is correct.

Note: Another defect which is known as Schottky defect,which is actually a type of point defect or imperfection in solids caused by a vacant space that is formed in a crystal lattice because of the atoms or ions leaving out from the interior to the surface of the crystal.
 Because of the large number of Schottky defects lower down the density of the crystal. Whenever the Frenkel defect alone is there, no decrease occurs in density. The closeness of the charge brought by the Frenkel defect focuses to raise the dielectric constant of the crystal. Compounds with such defects form electricity to a small extent.
In Schottky defect, an atom comes from the inside of the crystal to its surface, keeping behind an isolated vacancy. In the Frenkel defect, an atom comes to a new position b/w other atoms of the solid.