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प्रश्न
Schottky defect is observed in crystals when ______.
विकल्प
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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उत्तर
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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संबंधित प्रश्न
Explain the following term with suitable examples:
Frenkel defect
Examine the given defective crystal:
Answer the following questions :
(i) What type of stoichiometric defect is shown by the crystal?
(ii) How is the density of the crystal affected by this defect?
(iii) What type of ionic substances show such defect?
Out of NaCl and AgCl, which one shows Frenkel defect and why?
Answer the following question.
What type of stoichiometric defect is shown by ZnS and why?
Ionic solids containing large differences in sizes of ions show ____________.
Point defect is also known as ____________.
Type of stoichiometric defect shown by AgBr is ____________.
The following diagram shows:
Assertion: No compound has both Schottky and Frenkel defects.
Reason: Both defects change the density of the solid.
What is the effect of Frenkel defect on the density of ionic solids?
Cations are present in the interstitial sites in ______.
Frenkel defect is also known as:
(i) stoichiometric defect
(ii) dislocation defect
(iii) impurity defect
(iv) non-stoichiometric 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.
If NaCl is doped with 10–4 mole percent of SrCl2 the concentration of cation vacancies will be
