A compound that shows Schottky as well as Frenkel defect among the following is -

1. ZnS               

2. AgBr             

3. NaCl                 

4. AgCl

The edge length of fcc unit cell of NaCl is 508 pm.
If the radius of cation is 110 pm then radius of the anion is : 

1. 244 pm

2. 144 pm

3. 288 pm

4. 398 pm

The formula of nickel oxide with metal deficiency defect in its crystal is $N{i}_{0.98}O$. The crystal contains ${\mathrm{Ni}}^{2+} \mathrm{and} {\mathrm{Ni}}^{3+}$ ions. The fraction of nickel existing as $N{i}^{2+}$ ions in the crystal is-

1. 0.96

2. 0.04

3. 0.50

4. 0.31

In the spinel structrue, oxides ions are cubical-closest packed whereas 1/8th of tetrahedral voids are occupied by ${\mathrm{A}}^{2+}$ cation and 1/2 of octahedral voids are occupied by ${\mathrm{B}}^{3+}$ cations. The general formula of the compound having spinel structure is :

1. ${\mathrm{A}}_2{\mathrm{B}}_2{\mathrm{O}}_4$

2. ${\mathrm{AB}}_2{\mathrm{O}}_4$

3. ${\mathrm{A}}_2{\mathrm{B}}_4{\mathrm{O}}_2$

4. ${\mathrm{A}}_4{\mathrm{B}}_2{\mathrm{O}}_2$

An ionic compound has a unit cell consisting of A ions at the corners of a cube and B ions on the centers of the faces of the cube. The empirical formula for this compound would be : 

1. AB 

2. A₂B

3. AB₃

4. A₃B

An element crystallizes in a structure having FCC unit cell of an edge length 200 pm. If
200 g 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

Ionic radii of Mg²⁺ and O^2- ions are 66 pm and 140 pm respectively. The type of interstitial void and coordination number of Mg²⁺ ion respectively are

1. Tetrahedral, 12

2. Octahedral, 6

3. Tetrahedral, 6

4. Octahedral, 8

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. ${\mathrm{C}}_3{\mathrm{A}}_4$

2. ${\mathrm{C}}_2{\mathrm{A}}_3$

3. ${\mathrm{C}}_3{\mathrm{A}}_2$

4. ${\mathrm{C}}_4{\mathrm{A}}_3$

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 $g/c{m}^3$

2. 0.425 $g/c{m}^3$

3. 8.25 $g/c{m}^3$

4. 4.25 $g/c{m}^3$

For a cubic crystal structure, which one of the following relations indicating the cell characteristic is correct?

1. $a\ne b\ne c$ $and$ $\alpha \ne \beta$ $and$ $\gamma \ne 90°$

2. $a\ne b\ne c$ $and$ $\alpha =\beta$ $=$ $\gamma =90°$

3. $a=b=c$ $and$ $\alpha \ne \beta$ $=$ $\gamma =90°$

4. $a=b=c$ $and$ $\alpha =\beta =$ $\gamma =90°$