Solid State · Question 21

Structure of a mixed oxide is cubic close packed (ccp). The cubic unit cell of mixed oxide is composed of oxide ions. One fourth of the tetrahedral voids are occupied by divalent metal A and the octahedral voids are occupied by a monovalent metal B. The formula of the oxide is

1. ABO2
2. A2BO2
3. A2B3O4
4. AB2O2

A metal crystallises with a face-centred cubic lattice. The edge of the unit cell is 408 pm. The diameter of the metal atom is

1. 288 pm
2. 408 pm
3. 144 pm
4. 204 pm

The number of octahedral void(s) per atom present in a cubic close-packed structure is

1. 1
2. 3
3. 2
4. 4

A solid compound XY has NaCl structure. If the radius of the cation is 100 pm, the radius of the anion (Y-) will be

1. 275.1 pm
2. 322.5 pm
3. 241.5 pm
4. 165.7 pm

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 is

1. 335 pm
2. 250 pm
3. 200 pm
4. 300 pm

Sodium has body centred packing. Distance between two nearest atoms is 3.7 A. The lattice parameter is

1. 4.3 A
2. 3.0 A
3. 8.6 A
4. 6.8 A

Lithium metal crystallises in a body-centred cubic crystal. If the length of the side of the unit cell of lithium is 351 pm, the atomic radius of lithium will be

1. 151.8 pm
2. 75.5 pm
3. 300.5 pm
4. 240.8 pm

Copper crystallises in a face-centred cubic lattice with a unit cell length of 361 pm. What is the radius of copper atom in pm?

1. 157
2. 181
3. 108
4. 128

If the lattice parameter for a crystalline structure is 3.6 A, then the atomic radius in fcc crystal is

1. 2.92 A
2. 1.27 A
3. 1.81 A
4. 2.10 A

Percentage of free space in a body centred cubic unit cell is

1. 34%
2. 28%
3. 30%
4. 32%