Q 1.
AB ABA ……….. represents and arrangement of layers called :
(a) hexagonal dosed packing
(b) cubic closed packing
(c) body centered cubic packing
(d) fluorite close packing
Q 2.
The number of molecules per unit cell which crystallizes in the form of end face centered
(monodlinic) lattice with a molecule at each lattice site:
(a) 1
(b) 2
(c) 4
(d) 6
Q 3.
In diamond the co-ordination number of carbon is:
(a) 4 and its unit cell has 8 carbon atoms
(b) 4 and its unit cell has 6 carbon atoms
(c) 6 with 4 carbon atoms is unit cell
(d) 4 with 4 carbon atoms in unit cell
Q 4.
Which of the following crystals does not have 8 : 8 co-ordination?
(a) NH4Cl
(b) AlFe
(c) MnO
(d) NH4Br
Q 5.
The bond length and bond angles in molecules in the solid state are calculated by X-rays
diffraction technique because X-rays are scattered by:
(a) nucleus
(b) protons
(c)c neutrons only
(d) electrons only
Q 6.
Mark the incorrect statement:
(a) In hcp and ccp both, a sphere is in contact with 6 spheres of its own layer
(b) In both hcp and ccp the sphere has 3 sphere above it and 3 below it
(c) In both hcp and ccp the co-ordination number is 12
(d) In inverse spinel (e.g. magnetite, Fe3O4) only dipositive ions occupy octahedral voids
while tripositive ions occupy tetrahedral voids
Q 7.
A compound formed by elements A and B crystallises in cubic structure, in which atoms
of A are at the corners while that of B are at the face Centre. The formula of the
compound is :
(a) AB3
(b) AB
(c) A3B
(d) non of these
Q 8.
Na atom crystallises in bcc lattice with cell edge (a) = 4.29 Å. The radius of Na atom is:
(a) 18.6 Å
(b) 1.86 Å
(c) 1.86 pm
(d) 1.860 pm
Q 9.
Pick out the incorrect statement:
(a) NaCl structure transform to CsCl structure on heating
(b) In CaF2 structure, each F-1 ion is co-ordinated by 4 Ca2+ ions and each Ca++ ion is coordinated by 8 F- ions
(c) NaCl has 6:6 co-ordination, while CsCl is with 8:8 co-ordination
(d) In Na2O each oxide ion is co-ordinated by 8 Na+ ions and each Na ion by 4 oxide ions
Q 10. NaCl is doped with 2 × 10-3 mole % of SrCl2. The concentration of cation vacancies is:
(a) 6.02 × 1018 per mol
(b) 12.04 × 1018 per mol
18
(c) 3.01 × 10 per mol
(d) 12.04 × 1020 per mol
Q 11. CaO and NaC1 have the same crystal structure and nearly the same ionic radii, if x is the
lattice energy of NaCl, the lattice energy of CaO is very nearly:
(a) 2x
(b) x
(c) 4x
(d) x/2
Q 12. Which of the following expression is correct for a CsCl unit cell with lattice parameter a
?
(a) C s  Cl   2a
(b) Cs  Cl   a / 2
(c) C s  Cl  
3
a
2
(d) C s  Cl  
3a
2
Q 13. Which of the following crystals have 6:6 co-ordination ?
(a) NH4I
(b) MnO
(c) ZnS
(d) None of these
Q 14. Match list-I with list-II and select the correct answer by using the codes given below:
List-I
List II
(Shape)
(Radius ratio)
(A) Planar tri
1. 0.732
(B) Square planar
2. 0.225
(C) Body centered cubic
3. 0.115
(D) Tetrahedral
4. 0.414
A
B
C
D
A
B
C
D
(a)
3
4
1
2
(b)
3
2
1
4
(c)
2
1
4
3
(d)
1
3
4
2
Q 15. Calculate the ionic radius of a Cs+ ion assuming the cell edge length for Cs Cl is 0.4123
nm and that the ionic radius of a Cl- ion is 0.181 nm:
(a) 0.176 nm
(b) 0.231 nm
(c) 0.358 nm
(d) 0.116 nm
Q 16. Because of anisotropy:
(a) mica cleaves into long rod like peices and asbestos cleaves into thin sheets
(b) mica as well as asbestos cleaves into thin sheets
(c) mica cleaves into thin sheets and asbestos cleaves into long rod like peices
(d) mica as well as asbestos cleaves into long rod like
Q 17. Which of the following crystals has 4: 4 co-ordination ?
(a) HgS
(b) NH
(c) NaC1
(d) None of these
Q 18. The hcp and ccp structure for a given element would be expected to have:
(a) the same alignments of layers
(b) the same density
(c) the same packing fraction
(d) all the above
Q 19. Which of the following statements is correct?
(a) The co-ordination number of each ion in a CsCl crystal is 9
(b) A metal that crystallizes in a bcc structure has a co-ordination number of 12
(c) A unit cell of an ionic crystal shares some of its ions with other unit cells
(d) The length of unit cell in NaC1 is 552 pm with rNa = 95 pm and rCl = 181 pm
Q 20. Iron crystalizes in a bcc system with a lattice parameter of 2.861Å. Calculate the density
of iron in it (at. wt. of iron = 56, NA = 6.02 × 1023 per mol)
(a) 7.92 g/mL
(b) 8.96 g/mL
(c) 2.78 g/L
(d) 6.72 g/mL
Q 21. Which of the following statements is incorrect ?
(a) A substitutional solid solution is one in which atoms of the solute metal occupy same
locations that solvent metal atoms are expected to occupy
(b) An interstitial solid solution is one in. which the solutes atoms occupy the interstices
between the solvent atoms
(c) An intermediate compound is a compound formed between metals and metalloids
(d) Cu is an intermetallic compound
Q 22. M2X have a structure closely related to that of fluorite. It is actually reverse of fluorite
structure hence called, Antifluorite structure. In such a structure:
(a) smaller cations occupy the position of fluoride ions and larger anions that of Ca2+
ions:
(b) larger cations occupy the position of F- ions and smaller anions that of Ca2+ ions
(c) each F- is surrounded by 4 Ca++ in tetrahedral arrangement
(d) F- ions occupy all the 8 octahedral voids
Q 23. The incorrect statement for sphalerite, atom of ZnS is:
(a) It structure is similar to diamond except that alternate atoms are Zn and S
(b) Because the S2- is larger than the Zn ion only 6 rather then 4 or 8 sulphide ions can be
packed around a Zn ion
(c) As S2- is larger than Zn2+ only 4 rather than 6 or 8 s2- can be packed around Zn2+
(d) ZnS is a polar covalent compound
Q 24. The fluorite structure shows 8 : 4 co-ordination. Which of the following lattices have
fluorite live structure?
(a) SrCl2
(b) BaF2
(c) ThO2
(d) All of these
Q 25. In an NaC1 structure, all the:
(a) octahedral voids are unoccupied
(b) tetrahedral voids are unoccupied
(c) octahedral as well as tetrahedral voids occupied
(d) octahedral as well as tetrahedral voids unoccupied
Q 26. Which of the following structures hive. layered lattices?
(a) Diamond
(b) Ice
(c) Cadmium iodide (d) All of these
Q 27. TiO2 (rutile) shows 6:3 co-ordination. The solid having rutile like structure among the
following is:
(a) ZnS
(b) KCl
(c) SnO2
(d) none of these
Q 28. The statement correct for rock salt structure is:
(a) the tetrahedral voids are larger than octahedral voids
(b) the tetrahedral voids are unoccupied while octahedral voids are occupied by cations
(c) the radius ratio is 0.732
(d) the radius ratio is 0.999
Q 29. How many octahedral voids are there per sphere in a ccp structure?
(a) 4
(b) 2
(c) 1
(d) 6
Q 30. Which of the following crystals shows 4 : 2 co-ordination?
(a) CaF2
(b) SiO2
(c) PbO2
(d) None of these
Q 31. The co-ordination number of fcc structure for metals is 12, since:
(a) each atom touches 4 others in same layer, in layer above and 3 in layer below
(b) each atom touches 4 others in same layer, 4 in layer I above and 4 In layer below
(c) each atom touches 6 others in same layer, 6 in layer above and 6 in layer below
(d) each atom touches 3 others in same layer, 6 in layer above and 6 in layer below
Q 32. Amorphous solids may be classified as:
(a) isotropic and super-cooled liquids
(c) isoenthalpic and super-heated liquids
(b) anisotropic and super-cooled liquids
(d) isotropic and super-heated solids.
Q 33. Correct statement for ccp is:
(a) Each octahedral void is surrounded by 6 spheres and each sphere is surrounded by 3
octahedral voids
(b) Each octahedral void is surrounded by 6 spheres and each sphere is surrounded by 6
octahedral voids
(c) Each octahedral void is surrounded by 6 spheres and each sphere is surrounded by 8
octahedral voids
(d) Each octahedral void is surrounded by 6 spheres and each sphere is surrounded by 12
octahedral voids
Q 34. If hcp and ccp structures are made up of spheres of equal size. The volume occupied per
sphere is (given r = radius of sphere):
(a) 1.33 r3
(b) 5.66 r3
(c) 2.66 r3
(d) 7.40 r3
Q 35. F-centres are:
(a) the electrons trapped in anionic vacancies
(b) the electrons trapped in cation vacancies
(c) non-equivalent sites of stoichiometric compounds
(d) all of the above
Answers
1.
8.
15.
22.
29.
a
c
a
a
c
2.
9.
16.
23.
30.
b
c
c
b
b
3.
10.
17.
24.
31.
a
b
a
a
b
4.
11.
18.
25.
32.
c
c
c
c
a
5.
12.
19.
26.
33.
d
c
c
c
b
6.
13.
20.
27.
34.
d
a
a
c
b
7.
14.
21
28
35.
a
a
c
c
a