Graphite and diamond are ________.

(a)

Covalent and molecular crystals

(b)

ionic and covalent crystals

(c)

both covalent crystals

(d)

both molecular crystals

An ionic compound A_x B_y crystallizes in fcc type crystal structure with B ions at the centre of each face and A ion occupying corners of the cube the correct formula of A_xB_y is ________.

(a)

AB

(b)

AB₃

(c)

A₃B

(d)

A₈B₆

The ratio of close packed atoms to tetrahedral hole in cubic packing is ________.

(a)

1:1

(b)

1:2

(c)

2:1

(d)

1:4

Solid CO₂ is an example of ________.

(a)

Covalent solid

(b)

metallic solid

(c)

molecular solid

(d)

ionic solid

In calcium fluoride, having the flurite structure the coordination number of Ca²⁺ ion and F^- Ion are ________.

(a)

4 and 2

(b)

6 and 6

(c)

8 and 4

(d)

4 and 8

The number of unit cells in 8 gm of an element X (atomic mass 40) which crystallizes in bcc pattern is (N_A is the Avogadro number)________.

(a)

6.023 x 10²³

(b)

6.023 x 10²²

(c)

60.23 x 10²³

(d)

\(\left( \frac { 6.023\times { 10 }^{ 23 } }{ 8\times 40 } \right) \)

In a solid atom M occupies ccp lattice and \(\left( \frac { 1 }{ 3 } \right) \) of tetrahedral voids are occupied by atom N. Find the formula of solid formed by M and N ________.

(a)

MN

(b)

M₃N

(c)

MN₃

(d)

M₃N₂

The ionic radii of A⁺ and B⁻ are 0.98 x 10^-10 m and 1.81 x 10^-10 m. the coordination number of each ion in AB is ________.

(a)

8

(b)

2

(c)

6

(d)

4

CsCl has bcc arrangement, its unit cell edge length is 400pm, its inter atomic distance is ________.

(a)

400pm

(b)

800pm

(c)

\(\sqrt { 3 } \times 100pm\)

(d)

\(\left( \frac { \sqrt { 3 } }{ 2 } \right) \times 400pm\)

A solid compound XY has NaCl structure if the radius of the cation is 100pm, the radius of the anion will be ________.

(a)

\(\left( \frac { 100 }{ 0.414 } \right) \)

(b)

\(\left( \frac { 0.732 }{ 100 } \right) \)

(c)

100 x 0.414

(d)

\(\left( \frac { 0.414 }{ 100 } \right) \)

The vacant space in bcc lattice unit cell is ________.

(a)

48%

(b)

23%

(c)

32%

(d)

26%

The radius of an atom is 300pm, if it crystallizes in a face centered cubic lattice, the length of the edge of the unit cell is ________.

(a)

488.5pm

(b)

848.5pm

(c)

884.5pm

(d)

484.5pm

The fraction of total volume occupied by the atoms in a simple cubic is ________.

(a)

\(\left( \frac { \pi }{ 4\sqrt { 2 } } \right) \)

(b)

\(\left( \frac { \pi }{ 6 } \right) \)

(c)

\(\left( \frac { \pi }{ 4 } \right) \)

(d)

\(\left( \frac { \pi }{ 3\sqrt { 2 } } \right) \)

The yellow colour in NaCl crystal is due to ________.

(a)

excitation of electrons in F centers

(b)

reflection of light from Cl^- ion on the surface

(c)

refraction of light from Na⁺ ion

(d)

all of the above

If ‘a’ stands for the edge length of the cubic system sc, bcc, and fcc. Then the ratio of radii of spheres in these systems will be respectively ________.

(a)

\(\left( \frac { 1 }{ 2 } a;\frac { \sqrt { 3 } }{ 2 } a;\frac { \sqrt { 2 } }{ 2 } a \right) \)

(b)

\(\left( \sqrt { 1a } :\sqrt { 3a } :\sqrt { 2a } \right) \)

(c)

\(\left( \frac { 1 }{ 2 } a:\frac { \sqrt { 3 } }{ 4 } a:\frac { 1 }{ 2\sqrt { 2 } } a \right) \)

(d)

\(\frac { 1 }{ 2 } a:\sqrt { 3 } a:\frac { 1 }{ \sqrt { 2 } } a\)

If ‘a’ is the length of the side of the cube, the distance between the body centered atom and one corner atom in the cube will be_________.

(a)

\(\left( \cfrac { 2 }{ \sqrt { 3 } } \right) a\)

(b)

\(\left( \cfrac { 4 }{ \sqrt { 3 } } \right) a\)

(c)

\(\left( \cfrac { \sqrt { 3 } }{ 4 } \right) a\)

(d)

\(\left( \cfrac { \sqrt { 3 } }{ 2 } \right) a\)

Potassium has a bcc structure with nearest neighbor distance 4.52 \(\overset{o}{A}\). Its atomic weight is 39. its density will be_______.

(a)

915 kg m^-3

(b)

2142 kg m^-3

(c)

452 kg m^-3

(d)

390 kg m^-3

Schottky defect in a crystal is observed when ______.

(a)

unequal number of anions and anions are missing from the lattice

(b)

Equal number of cations and anions are missing from the lattice

(c)

an ion leaves its normal site and occupies an interstitial site

(d)

no ion is missing from its lattice

The cation leaves its normal position in the crystal and moves to some interstitial position, the defect in the crystal is known as _____.

(a)

Schottky defect

(b)

F center

(c)

Frenkel defect

(d)

non-stoichiometric defect

The crystal with a metal deficiency defect is ________.

(a)

NaCl

(b)

FeO

(c)

ZnO

(d)

KCl

A two dimensional solid pattern formed by two different atoms X and Y is shown below. The black and white squares represent atoms X and Y respectively. The simplest formula for the compound based on the unit cell from the pattern is _______.

(a)

XY₈

(b)

X₄Y₉

(c)

XY₂

(d)

XY₄