An element crystallizes in a structure having FCC unit cell of an edge length 200 pm. If 200 g of this element contains 24 x 1023 atoms, the density of the element is -
1. 50.3 g/cc
2. 63.4 g/cc
3. 41.6 g/cc
4. 34.8 g/cc
If NaCl is doped with mol% of , the number of cation vacancies will be -
1.
2.
3.
4. 2
A compound that shows Schottky as well as Frenkel defect among the following is -
1. ZnS
2. AgBr
3. NaCl
4. AgCl
The formula of nickel oxide with metal deficiency defect in its crystal is . The crystal contains ions. The fraction of nickel existing as ions in the crystal is-
1. 0.96
2. 0.04
3. 0.50
4. 0.31
A compound is formed by cation C and anion A. The anions form hexagonal close packed (hcp) lattice and the cations occupy 75 % of octahedral voids. The formula of the compound is:
1.
2.
3.
4.
The appearance of colour in solid alkali metal halides is generally due to:
1. F-centres.
2. Schottky defect.
3. Frenkel defect.
4. Interstitial positions.
CsBr crystallises in a body-centered cubic lattice. The unit cell length is 436.6 pm. Given that the atomic mass of Cs = 133 amu and that of Br = 80 amu and the Avogadro number being 6.02×1023 mol-1, the density of CsBr is:
1. 42.5
2. 0.425
3. 8.25
4. 4.25
The fraction of total volume occupied by the atoms present in a simple cube is:
1.
2.
3.
4.
Silicon gives p-type of semiconductor on doping with:
1. Germanium.
2. Arsenic.
3. Selenium.
4. Boron.