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प्रश्न
Why is FeO (s) not formed in stoichiometric composition?
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उत्तर
In the crystals of FeO, some of the Fe2+ cations are replaced by Fe3+ ions. Three Fe2+ ions are replaced by two Fe3+ ions to make up for the loss of positive charge. Eventually there would be less amount of metal as compared to stoichiometric proportion.
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संबंधित प्रश्न
Explain the following term with a suitable example:
Interstitials
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?
Out of NaCl and AgCl, which one shows Frenkel defect and why?
Point defect is also known as ____________.
Dislocation defect is also known as ____________.
Frenkel defects are not found in alkali metal halides because ____________.
Type of stoichiometric defect shown by AgBr is ____________.
In a Schottky defect ____________.
Which of the following point defects are shown by AgBr(s) crystals?
- Schottky defect
- Frenkel defect
- Metal excess defect
- Metal deficiency defect
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.
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
Schottky defect is noticed in ______
