JEE Advanced2009ChemistrySolid StateActual
The correct statement(s) regarding defects in solids is (are)
Options
- AFrenkel defect is usually favoured by a very small difference in the sizes of cation and anion
- BFrenkel defect is a dislocation defect
- CTrapping of an electron in the lattice leads to the formation of F-centre
- DSchottky defects have no effect on the physical properties of solids
Correct answer
B. Frenkel defect is a dislocation defect
Step-by-step solution
(a) Wrong Frenkel defect is favoured when the difference in ionic radii is very large. In the given case Schottky defect is favoured. (b) Correct Frenkel defect arises due to dislocation of smaller ion from its normal lattice point to the interstitial space. (c) Correct When alkali metal in the gaseous state is passed over salts like NaCl , electrons from metal are trapped in the interstitial space giving rise to F-centre defect which is a type of Frenkel defect. (d) Wrong Schottky defect affects physical propertie