The total number of tetrahedral voids in 0.5 mol compound in  hexagonal close-packed structure is-

1. 4.022 ×1022
2. 5.022 ×1023
3. 6.022 ×1023
4. 5.022 ×1022

Subtopic:  Voids, Radius Ratio & Coordination Number |
 73%
Level 2: 60%+
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A compound is formed by two elements M and N. The element N forms ccp and atoms of M occupy 1/3rd of tetrahedral voids. The formula of the compound is-

1. M3 N2
2. M2 N3
3. MN3
4. MN
Subtopic:  Voids, Radius Ratio & Coordination Number |
 78%
Level 2: 60%+
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The lattices has the highest packing efficiency among the following is- 
1. Simple cubic
2. Body-centred cubic
3. Hexagonal close-packed lattice
4. None of the above

 

Subtopic:  Density & Packing Fraction |
 86%
Level 1: 80%+
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An element with molar mass 2.7 × 10-2 kg mol-1 forms a cubic unit cell with edge length 405 pm. If its density is 2.7 × 103 kg m−3, then the nature of the cubic unit cell is-

1. Face-centred cubic
2. Body-centered cubic
3. End-Centred cubic
4. None of the above
Subtopic:  Density & Packing Fraction |
 71%
Level 2: 60%+
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Heating of a solid favour the - 

1. Metal deficiency defect
2. Impurity defects
3. Vacancy defect
4. None of the above
 
Subtopic:  Imperfections in Solids & Semiconductors |
 61%
Level 2: 60%+
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Statement 1: ZnS shows Frenkel defect.
Statement 2: AgBr shows Frenkel as well as Schottky defect.

1. Statement 1 is true , statement 2 is false.
2. Statement 1 is false , statement 2 is true.
3. Both statements are true.
4. Both statements are false.
Subtopic:  Imperfections in Solids & Semiconductors |
 84%
Level 1: 80%+
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When a cation of higher valency is added as an impurity in an ionic solid, then : 

1. Vacancies are created .
2. Stoichiometry remains unaffected.
3. Excess of metal ions is created.
4. Both (2) and (3) 
Subtopic:  Imperfections in Solids & Semiconductors |
Level 3: 35%-60%
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The ionic solid among the following, that has anionic vacancy due to metal excess, defect and develop color is-

1.  KCl
2. NaCl
3. TiO
4. All of the above
Subtopic:  Imperfections in Solids & Semiconductors |
 74%
Level 2: 60%+
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A group 14 element is converted into n-type semiconductor by doping it with : 

1. Boron 
2. Aluminium
3. Phosphorous
4. All of the above.

 

Subtopic:  Imperfections in Solids & Semiconductors |
 76%
Level 2: 60%+
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Substances used for making permanent magnets are :
 
1. Ferrimagnetic
2. Ferromagnetic
3. Antiferromagnetic 
4. Both (1) and (3) 
Subtopic:  Imperfections in Solids & Semiconductors |
 78%
Level 2: 60%+
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