Iron has a body centred cubic unit cell with the cell dimension of 286.65 pm. Density of iron is 7.87 g cm-3. The value of Avogadro's number based on this data will be -
(Atomic mass of Fe = 56.0 u)
1. 6.04 x 1023 mol-1
2. 12.08 x 1024 mol-1
3. 6 x 1022 mol-1
4. 6 x 10-23 mol-1
Iodine crystals are classified as-
1. Metallic solids.
2. Ionic solids.
3. Molecular solids .
4. Covalent solids.
If Xenon crystallizes in face center cubic lattice and the edge of the unit cell is 620 pm, then the radius of the Xenon atom is-
1. 219.20 pm
2. 438.5 pm
3. 265.5 pm
4. 536.94 pm
In a cubic unit cell, atom A is present at each corner, atom B at each face centre and atom C at the body centre. The simplest formula of the solid is :
1.
2.
3.
4.
The unit cell dimensions of a cubic lattice (edges a, b, c and the angles between them, α, β, γ) are :
1. a = b = c,
2. a = b c,
3. a = b = c,
4. a b c,
a. | The coordination number of a cation occupying a tetrahedral hole is 4. |
b. | The coordination number of a cation occupying an octahedral hole is 6. |
c. | In Schottky defect, the density of the lattice decreases. |
1. a, b
2. b, c
3. a, b, c
4. a, c
The incorrect statement among the following is:
1. | The fraction of the total volume occupied by the atoms in a primitive cell is 0.48. |
2. | Molecular solids are generally volatile. |
3. | The number of carbon atoms in a unit cell of diamond is 8. |
4. | The number of Bravais lattices in which a crystal can be categorized is 14. |
A metallic element exists as a cubic lattice. Each edge of the unit cell is 2.88 Å. The density of the metal is 7.20 g cm–3. The number of unit cells, that will be present in 100 gm of the metal is:
1. 5.82 × 1023
2. 16.33 × 1023
3. 7.49 × 1024
4. 6.9 × 1024
In which of the following crystals are alternate tetrahedral voids occupied:
1. NaCl
2. ZnS
3. CaF2
4. Na2O
AB crystallizes in a body-centred cubic lattice with edge length a equal to 387 pm. The distance between two oppositely charged ions in the lattice will be :
1. 250 pm
2. 200 pm
3. 300 pm
4. 335 pm