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Question
Schottky defect is observed in crystals when ______.
Options
some cations move from their lattice site to interstitial sites.
equal number of cations and anions are missing from the lattice.
some lattice sites are occupied by electrons.
some impurity is present in the lattice.
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Solution
Schottky defect is observed in crystals when equal number of cations and anions are missing from the lattice.
Explanation:
| Defect | Definition | Type of solid |
Effect of defect on density of substance |
Structure of crystal (with defect) |
| Schottky defect |
A crystal is said to have Schottky defect if equal number of cations and anions are missing from their normal lattice site there by creating vacancies or holes. |
Ionic solid |
Decreases |  Schottky defect in a crystal |
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RELATED QUESTIONS
Explain the following term with suitable examples:
Frenkel defect
Explain the following term with a suitable example:
Interstitials
What type of defect is shown by NaCl in
stoichiometric defects, and
Defect shown by non-ionic solids is ____________.
Frenkel defects are not found in alkali metal halides because ____________.
The radius of Cs+ is 169 pm and Cl− is 181 pm. The radius ratio is ____________.
Type of stoichiometric defect shown by AgBr is ____________.
The following diagram shows:
Which is not correct about the Schottky defects?
Assertion: No compound has both Schottky and Frenkel defects.
Reason: Both defects change the density of the solid.
Assertion: Due to Frenkel defect, there is no effect on the density of the crystalline solid.
Reason: In Frenkel defect, no cation or anion leaves the crystal.
Alkali halids do not show Frenkel defect because ____________.
In a Schottky defect ____________.
Which of the following defects decrease the density?
(i) Interstitial defect
(ii) Vacancy defect
(iii) Frankel defect
(iv) Schottky defect
Why is FeO (s) not formed in stoichiometric composition?
Given below are two statements, one is labelled as Assertion (A) and the other is labelled as Reason (R):
Assertion: In any ionic solid (MX) with Schottky defects, the number of positive and negative ions are same.
Reason: Equal number of cation and anion vacancies are present.
Which type of ‘defect’ has the presence of cations in the interstitial sites?
