The number of octahedral voids per lattice site in a lattice is-

1. 2

2. 1

3. 4

4. 0

An element with molar mass 2.7 × 10^–2 kg mol^–1 forms cubic unit cell with edge length 405 pm. If its density is 2.7 × 10³ kg m^–3 , the radius of the element in  × 10^–12 m is approximately- 

1. 148

2. 143

3. 140

4. 152

A diatomic molecule X₂ has a body-centred cubic (bcc) structure with a cell edge of 300 pm. The density of the molecule is 6.17 g cm^–3 . The number of molecules present in 200 g of X₂ is-
(Avogadro constant (N_A) = 6 × 10²³ mol^–1)
1. 8 N_A
2. 40 N_A
3. 4 N_A
4. 2 N_A

A crystal is made up of metal ions '${\mathrm{M}}_1$' , '${\mathrm{M}}_2$', and oxide ions. Oxide ions form a CCP lattice structure. The cation '${\mathrm{M}}_1$' occupies 50% of octahedral voids and the cation '${\mathrm{M}}_2$' occupies 12.5% of tetrahedral voids of oxide lattice. The oxidation numbers of '${\mathrm{M}}_1$' and'${\mathrm{M}}_2$' are, respectively :
1. +2, +4
2. +3, +1
3. +1, +3
4. +4, +2

Element ‘B’ forms ccp structure and ‘A’ occupies half of the octahedral voids, while oxygen atoms occupy all the tetrahedral voids. The structure of bimetallic oxide is -
1.  $A_{2}B{O}_4$
2. $A_4{B}_{2}O$
3. $A{B}_2{O}_4$
4. $A_2{B}_{2}O$

The ratio of number of atoms present in a simple cubic, body centered cubic and face centered cubic structure are, respectively :

1. 8 : 1 : 6

2. 4 : 2 : 1

3. 1 : 2 : 4

4. 4 : 2 : 3

The type of 'defect' has the presence of cations in the interstitials sites is-

1. Schottky defect

2. Frenkel defect

3. Vacancy defect

4. Metal deficiency defect

The metallic as well as ferromagnetic compound among the following is-
1. TiO₂
2. CrO₂
3. VO₂
4. MnO₂

Sodium metal crystallizes in a body centred cubic lattice with a unit cell edge of 4.29 Å. The radius of sodium atom is approximately :

1. 1.86 Å

2.  3.22 Å

3.  5.72 Å

4.  0.93 Å

Experimentally it was found that a metal oxide has formula M_0.98O. Metal M, is present as M²⁺ and M³⁺ in its oxide. Fraction of the metal which exists as M³⁺ would be -

1. 6.05%

2. 5.08%

3. 7.01%

4. 4.08%