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प्रश्न
Which of the following statements are not true?
(i) Vacancy defect results in a decrease in the density of the substance.
(ii) Interstitial defects results in an increase in the density of the substance.
(iii) Impurity defect has no effect on the density of the substance.
(iv) Frankel defect results in an increase in the density of the substance.
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उत्तर
(iii) Impurity defect has no effect on the density of the substance.
(iv) Frankel defect results in an increase in the density of the substance.
Explanation:
(iii) Impurity defect changes the density of substance as impurity has different than the ion present on perfect crystal e.g., When SrCl2 is added to the NaCl crystal, it causes impurity defect.
(iv) Frenkel defect results neither decrease nor increase in density of substance.
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संबंधित प्रश्न
Explain the following term with suitable examples:
Frenkel defect
Give reasons : In stoichiometric defects, NaCl exhibits Schottky defect and not 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?
What type of defect is shown by NaCl in
stoichiometric defects, and
non-stoichiometric defects?
Defects in solids can be studied using
Frenkel defects are not found in alkali metal halides because ____________.
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 ____________.
What is the effect of Frenkel defect on the density of ionic solids?
Cations are present in the interstitial sites in ______.
Schottky defect is observed in crystals when ______.
Which of the following defects is also known as dislocation defect?
Frenkel defect is also known as:
(i) stoichiometric defect
(ii) dislocation defect
(iii) impurity defect
(iv) non-stoichiometric defect
Which of the following defects decrease the density?
(i) Interstitial defect
(ii) Vacancy defect
(iii) Frankel defect
(iv) Schottky defect
Match the defects given in Column I with the statements in given Column II.
| Column I | Column II |
| (i) Simple vacancy defect | (a) shown by non-ionic solids and increases density of the solid. |
| (ii) Simple interstitial defect | (b) shown by ionic solids and decreases density of the solid. |
| (iii) Frenkel defect | (c) shown by non ionic solids and density of the solid decreases. |
| (iv) Schottky defect | (d) shown by ionic solids and density of the solid remains the same. |
If NaCl is doped with 10–4 mole percent of SrCl2 the concentration of cation vacancies will be
Given below are two statements:
Statements I: Frenkel defects are vacancy as well as interstitial defects.
Statements II: Frenkel defect leads of colour in ionic solids due to the presence of F-centers.
Choose the most appropriate answer for the statements from the options given below:
