In a solid lattice, cation is absent from lattice site and present at an interstitial position, the

lattice defect is:

(a) Frenkel (b) Interstitial

(c) Schottky (d) None of these

The arrangement ABCABCABC.........is referred as

(a) octahedral close packing (b) hexagonal close packing

(c) tetrahedral close packing (d) cubic close packing

Frenkel defect is caused due to

(a) an ion missing from the normal lattice site creating a vacancy

(b) an extra positive ion occupying an interstitial position in the lattice

(c) an extra negative ion occupying an interstitial position in the lattice

(d) the shift of a positive ion from its normal lattice site to an interstitial site

The edge length of face centered unit cubic cell is 508 pm. If the radius of the cation is

110 pm, the radius of the anion is

(a) 144 pm (b) 288 pm

(c) 618 pm (d) 398 pm.

Schottky defect in crystals is observed when

(a) unequal number of cations 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) density of the crystal is increased.

A compound is formed by elements A and B. This crystallizes in the cubic structure

where the A atoms are at the corners of the cube and B atoms are at the body centres. The

simplest formula of the compound is

(a) AB (b) A B2

(c) AB2 (d) AB6

Potassium has a bcc structure with nearest neighbours distance 5.42Å. Its atomic weight

is 39. Its density will be

(a) 454 kg –3 m (b) 804 kg –3 m

(c) 852 kg –3 m (d) 908 kg –3 m .

An element (atomic mass = 100 g/mol) having BCC structure has cell edge 400 pm. The

density of element is (No. of atom in BCC (Z) = 2).

(a) 2.144 g/ 3 cm (b) 5.188 g/ 3 cm

(c) 7.289 g/ 3 cm (d) 10.376 g/ 3 cm .

Na and Mg crystallize in BCC and FCC crystals respectively, then the number of atoms

of Na and Mg presenting the unit cell of their respective crystal is

(a) 4 and 2 (b) 9 and 14

(c) 14 and 9 (d) 2 and 4.

A compound formed by elements A and B crystallizes in a cubic structure where A atoms

are at the corners of a cube and B atoms are at the face centre. The formula of the

compound is:

(a) AB3 (b) AB2

(c) AB4 (d) None of these

The density of KBr is 2.75 gm cm–3. Length of unit cell is 654 pm, K = 39, Br = 80, then

what is true about the predicted nature of the solid:

(a) Solid has face centred cubic system with coordination number = 6

(b) Solid has simple cubic system with coordination number = 4

(c) Solid has face centred cubic system with coordination number = 1

(d) None

A solid XY has NaCl structure. If radius of X+

is 100 pm. What is the radius of Y–

ion:

(a) 120 pm (b) 136.6 to 241.6 pm

(c) 136.6 pm (d) 241.6 pm

The co-ordination number of metal crystallizing in a hexagonal close packed structure is

(a) 12 (b) 4

(c) 8 (d) 6

The anions (A) form hexagonal closest packing and atoms (C) occupy only 2/3 of

octahedral voids in it, then the general formula of the compound is

(a) CA (b) C2A2

(c) C2A3 (d) C3A2

Silver iodide has the same structure as zinc sulfide, and its density is 5.67gcm–3. The edge

length of the unit cell is

(a) 4.50 Å (b) 5.50 Å

(c) 6.50 Å (d) 7.50 Å

In the closest packing of atom A of radius ra, the radius of atom B that can be fitted in

tetrahedral void is

(a) 0.225 ra (b) 0.155 ra

(c) 0.414 ra (d) 0.732 ra

Select the correct statements

CaCl2 doped with NaCl solid solution results in

(a) Substitutional cation vacancy (b) Frenkel’s defect

(c) Schottky defect (d) Decrease of density

Select the correct statement(s):-

(a) Schottky defect is shown by CsCl

(b) Frenkel defect is shown by Zns

(c) Hexagonal close packing (hcp) & Cubic close packing (ccp) structure has same co-

ordination no.12

(d) At high pressure, the co-ordination number increases.

Select the correct statement(s)

(a) At high pressure, the co-ordination no. increases from 6:6 to 8:8

(b) At high pressure, the co-ordination no. decreases from 8:8 to 6:6

(c) At high temperature, co-ordination number decreases

(d) At 760K temperature, CsCl structure changes into NaCl.

Which of the following statements are correct?

(a) Halides of all alkali metals and alkaline earth metals have rock salt structure

(b) Cesium halides and beryllium oxides have rock salt structure

(c) In zinc blende structure, sulphide ions are face centered and zinc is present in alternate

tetrahedral voids

(d) In FCC unit cell, void percentage = 26%

In face centered cubic unit cell

(a) Rank of unit cell is 3

(b) Face diagonal of the cube which is 2a is equal to 4r

(c) 8 tetrahedral voids per unit cell of FCC

(d) Effective no. of atoms is 4 in FCC

If we assume ‘M’ crystallizes in a fcc unit cell and tetrahedral voids are also occupied by

‘M’ atoms. If the edge length of the unit cell is 0.55 nm and the density of ‘M’ is 2.23

g/cc, which of the following statements are correct

(a) 40% of the tetrahedral voids are occupied by ‘M’-atoms in this lattice

(b) 50% of the tetrahedral voids are occupied by ‘M’-atoms in this lattice

(c) M-M bond length is equal to the sum of radii of 2 ‘M’ -atoms which is equal to

0.24 nm

(d) 20% of tetrahedral voids are occupied by ‘M’ –atoms in this lattice

Select the correct statement(s):

(a) Schottky defect is shown by CsCl

(b) Frenkel defectis shown by ZnS

(c) hcp and ccp structures have the same coordination number 12

(d) On increasing pressure, coordination number of CsCl decreases to that of NaCl

In Na2O structure:

(a) O2– ions constitute ccp and Na+

ions occupy all the octahedral holes

(b) O2– ions constitute ccp and Na+

ions occupy all the tetrahedral holes

(c) O2– ions constitute ccp and Na+

ions occupy 50% of tetrahedral holes and 100%

octahedral holes

(d) Na+ ions constitute ccp and O2– ions occupy half of octahedral holes

The hcp and ccp structure for a given element will have:

(a) The same density (b) The same fraction of unoccupied space

(c) The same coordination number (d) All of the above

Which of the following has antifluorite structure

(a) CaF2 (b) BaF2

(c) Li2O (d) Na2O

Which of the following has face-centred bravais lattice

(a) Hexagonal (b) Monoclinic

(c) cubic (d) Orthorhombic

Which of the following is/are correct statement(s) about ccp

(a) There are tetrahedral sites (b) There are octahedral sites

(c) There are cubic sites (d) All of the above