Defects in Crystal Structure

IMPORTANT

Defects in Crystal Structure: Overview

This Topic covers sub-topics such as Schottky Defects, Frenkel Defects, Vacancy Defects, Interstitial Defects, Types of Point Defects, Point Defects and Line Defects, Impurity Defects and, Imperfections in Crystalline Solids

Important Questions on Defects in Crystal Structure

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chemistry>Solid State>Defects in Crystal Structure> Q 1

Which of the following ionic compound will show Frenkel defect?

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chemistry>Solid State>Defects in Crystal Structure> Q 2

Which of the following point defect of crystals decreases the density of a solid?

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chemistry>Solid State>Defects in Crystal Structure> Q 3

Alkali halides do not show dislocation defect because

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chemistry>Solid State>Defects in Crystal Structure> Q 4

The number of Schottky defects present in $NaCl$ per ${cm}^{3}$ at room temperature is

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chemistry>Solid State>Defects in Crystal Structure> Q 5

Match List I with List II

	List-I (defect)		List-II (Examples)
(A)	Frenkel defects	(1)	$FeO$
(B)	Schottkey defects	(2)	$NaCl$
(C)	Vacancy defects	(3)	$AgCl$
(D)	Metal deficiency defects	(4)	Crystals with vacant lattice sites.

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chemistry>Solid State>Defects in Crystal Structure> Q 6

If molten $NaCl$ contains ${SrCl}_{2}$ as impurity, crystallization can generate

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chemistry>Solid State>Defects in Crystal Structure> Q 7

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$ .
Assertion $(A)$ : In a particular point defect, an ionic solid is electrically neutral, even if few of its cations are missing from its unit cells.
Reason $(R)$ : In an ionic solid, Frenkel defect arises due to dislocation of cation from its lattice site to interstitial site, maintaining overall electrical neutrality.

In the light of the above statements, choose the most appropriate answer from the options given below:

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chemistry>Solid State>Defects in Crystal Structure> Q 8

What are the consequences of schottky defect ?

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chemistry>Solid State>Defects in Crystal Structure> Q 9

By $X - ray$ diffraction methods, the unit length of $NaCl$ is observed to be $0.5627 nm$ . The density of $NaCl$ is found to be $2.164 g {cm}^{- 3}$ . What type of defect exists in the crystal ? Calculate the percentage of ${Na}^{+}$ and ${Cl}^{-}$ ions missing.