Solid State

A compound is formed by two elements A and B. The element B forms cubic close packed structure and atoms of A occupy 1/3 of tetrahedral voids. If the formula of the compound is AxBy, then the value of x+y is in option

1. 4
2. 3
3. 2
4. 5

What fraction of one edge centred octahedral void lies in one unit cell of fcc?

1. 13
2. 14
3. 112
4. 12

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). In the light of the above statements, choose the most appropriate answer from the options given below :

1. Both (A) and (R) are correct and (R) is the correct explanation of (A)
2. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
3. (A) is correct but (R) is not correct
4. (A) is not correct but (R) is correct

Copper crystallises in fcc unit cell with cell edge length of 3.608 10-8 cm. The density of copper is 8.92 g cm-3. Calculate the atomic mass of copper.

1. 63.1 u
2. 31.55 u
3. 60 u
4. 65 u

What fraction of Fe exists as Fe(III) in Fe0.96O ? (Consider Fe0.96O to be made up of Fe(II) and Fe(III) only)

1. 120
2. 112
3. 0.08
4. 116

The correct option for the number of body centred unit cells in all 14 types of Bravais lattice unit cells is :

1. 3
2. 7
3. 5
4. 2

Right option for the number of tetrahedral and octahedral voids in hexagonal primitive unit cell are :

1. 12, 6
2. 8, 4
3. 6, 12
4. 2, 1

An element has a body centered cubic (bcc) structure with a cell edge of 288 pm. The atomic radius is :

1. 24 288 pm
2. 4 3 288 pm
3. 4 2 288 pm
4. 34 288 pm

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. C3A4
2. C4A3
3. C2A3
4. C3A

Iron exhibits bcc structure at room temperature. Above 900°C, it transforms to fcc structure. The ratio of density of iron at room temperature to that at 900°C (assuming molar mass and atomic radii of iron remains constant with temperature) is

1. 3 2
2. 4 33 2
3. 3 34 2
4. 12

Lithium has a bcc structure. Its density is 530 kg m-3 and its atomic mass is 6.94 g mol-1. Calculate the edge length of a unit cell of lithium metal. (NA = 6.02 1023 mol-1)

1. 527 pm
2. 264 pm
3. 154 pm
4. 352 pm

The ionic radii of A+ and B- ions are 0.98 10-10 m and 1.81 10-10 m. The coordination number of each ion in AB is

1. 8
2. 2
3. 6
4. 4

In calcium fluoride, having the fluorite structure, the coordination numbers for calcium ion ( Ca2+) and fluoride ion (F-) are

1. 4 and 2
2. 6 and 6
3. 8 and 4
4. 4 and 8

The vacant space in bcc lattice unit cell is

1. 48%
2. 23%
3. 32%
4. 26%

The correct statement regarding defects in crystalline solids is

1. Frenkel defects decrease the density of crystalline solids
2. Frenkel defect is a dislocation defect
3. Frenkel defect is found in halides of alkali metals
4. Schottky defects have no effect on the density of crystalline solids

A given metal crystallises out with a cubic structure having edge length of 361 pm. If there are four metal atoms in one unit cell, what is the radius of one atom?

1. 80 pm
2. 108 pm
3. 40 pm
4. 127 pm

If a is the length of the side of a cube, the distance between the body centered atom and one corner atom in the cube will be

1. 2 3a
2. 4 3a
3. 34a
4. 32a

A metal has a fcc lattice. The edge length of the unit cell is 404 pm. The density of the metal is 2.72 g cm-3. The molar mass of the metal is (NA Avogadro's constant = 6.02 1023 mol-1)

1. 27 g mol-1
2. 20 g mol-1
3. 40 g mol-1
4. 30 g mol-1

The number of carbon atoms per unit cell of diamond unit cell is

1. 6
2. 1
3. 4
4. 8

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%

Which of the following statements is not correct?

1. The number of carbon atoms in a unit cell of diamond is 8
2. The number of Bravais lattices in which a crystal can be categorized is 14
3. The fraction of the total volume occupied by the atoms in a primitive cell is 0.48.
4. Molecular solids are generally volatile.