Chemistry
TOPIC : Solid state
Date :
1.
Marks : 120 mks | Time : ½ hr
Diamond is an example of
(a) Solid with hydrogen bonding (b)
(c) Covalent solid
(d)
Electrovalent solid
Glass
2. For tetrahedral coordination number, the radius ratio
(a) 0 .732 − 1 .000
3.
(b)
0 . 414 − 0 . 732
(c)
rc +
ra −
is
0 . 225 − 0 . 414
(d) 0 .155 − 0 .225
An element (atomic mass 100 g / mol ) having bcc structure has unit cell edge 400 pm . Then density of
the element is
(a) 10 . 376 g / cm 3
(b) 5 .188 g / cm 3
(c)
7 .289 g / cm 3
(d) 2.144 g / cm 3
4. How many chloride ions are there around sodium ion in sodium chloride crystal
(a) 3
(b) 8
(c) 4 (d) 6
5. Schottky defect in crystals is observed when
(a) Density of crystal is increased
(b) Unequal number of cations and anions are missing from the lattice
(c) An ion leaves its normal site and occupies an interstitial site
(d) Equal number of cations and anions are missing from the lattice
6. In AgBr crystal, the ion size lies in the order Ag + << Br − . The AgBr crystal should have the following
characteristics
(a) Defectless (perfect) crystal (b) Schottky defect only
(c) Frenkel defect only
(d) Both Schottky and Frenkel defects
7. In a solid lattice the cation has left a lattice site and is located at an interstitial position, the lattice defect is
(a) Interstitial defect
(b) Valency defect
(c)
Frenkel defect
(d) Schottky
chottky defect
8.
A compound is formed by elements A and B. This crystallizes in the cubic structure when atoms A
are the corners of the cube and atoms B are at the centre of the body. The simplest formula of the
compounds is
(a) AB
(b) AB 2
(c) A 2 B
(d) AB 4
9.
The number of atoms in 100 g of an
fcc
crystal with density d = 10 g / cm 3 and cell edge equal to
100 pm , is equal to
(a)
4 × 10 25
(b)
3 × 10 25
(c)
2 × 10 25
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(d)
1 × 10 25
Chemistry
10. In a face centred cubic cell, an atom at the face contributes to the unit cell
(a) 1/4 part
(b) 1/8 part
(c) 1 part (d) 1/2 part
11. Na and Mg crystallize in BCC and FCC type crystals respectively, then the number of atoms of Na and
present in the unit cell of their respective crystal is
a) 4 and 2
(b) 9 and 14 (c) 14 and 9
(d) 2 and 4
Mg
12. An ionic compound has a unit cell consisting of A ions at the corners of a cube and B ions on the centres of the
faces of the cube. The empirical formula for this compound would be
(a) AB
(b) A 2 B
(c) AB 3
(d) A 3 B
13. The edge length of face centred unit cubic cell is 508 pm . If the radius of the cation is 110 pm , the radius
of the anion is
618 pm
(a) 285 pm
(b) 398 pm
(c) 144 pm
(d)
14. Which set of characteristics of ZnS crystal is correct
(a) Coordination number (4 : 4); ccp; Zn++ ion in the alternate tetrahedral voids
(b) Coordination number (6 : 6); hcp; Zn++ ion in all tetrahedral voids
(c) Coordination number (6 : 4); hcp; Zn++ ion in all octahedral voids
(d) Coordination number (4 : 4);; ccp; Zn++ ion in all tetrahedral voids
15. Copper crystallizes in fcc with a unit cell length of 361pm. What is the radius of copper atom
(a) 108pm
(b) 127pm
(c) 157pm
(d) 181pm
16. A metal crystallizes with a face-centered
centered cubic lattice. The edge of the unit cell is 408pm. The diameter of
the metal atom is
(a) 288pm
(b) 408pm
(c) 144pm
(d) 204pm
17. Davy and Faraday proved that
(a) Diamond is a form of carbon
bon
(b) The bond lengths of carbon containing compounds are always equal
(c) The strength of graphite is minimum compared to platinum
(d) Graphite is very hard
18. How many space lattices are obtainable from the different crystal systems
(a) 7
(b) 14
(c) 32
(d) 230
19. In a face-centered
centered cubic lattice, a unit cell is shared equally by how many unit cells
(a) 8 (b) 4 (c) 2 (d) 6
20. If ‘a’ stands for the edge length of the cubic systems : smple cubic, body centred cubic and face centred
cubic, then the ratio of radii of the spheres in these systems will be respectively
(a)
:
√
:
√
(b) 1 : √3 : √2
(c)
:
√
:
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√
(d)
: √3 :
√
Chemistry
21. Which type of solid crystals will conduct heat and electricity
(a) Ionic
(b) Covalent
(c) Metallic
(d)
Molecular
22. In a face centred cubic lattice, atom A occupies the corner one atom of B is missing from one of the face
centred points, the formula of the compound is
(a) A2B
(b) AB2
(c) A2B3
(d) A2B5
23. Percentages of the free space in cubic close packed structure and is body centered packed structure are
respectively
(a) 48% and 26%
b) 30% and 26%
(c) 26% and 32% (d) 32% and 48%
24. Body centered cubic lattice has a coordination number of
(a) 4
(b) 8
(c) 12
(d) 6
25. Which of the following statements is correct for CsBr3
(a) It is a covalent compound
(b)
It contains Cs 3 + and Br − ions
−
+
(c) It contains Cs and Br3 ions
(d) It contains Cs + , Br − and lattice Br2 molecule
26. The basic building unit of all silicates is
(a) SiO 4 square planar (b) [SiO 4 ] 4 − tetrahedron (c)
SiO 4 octahedron
(d) SiO 4 linear
27. What type of crystal defect is indicated in the diagram below
Na + Cl − Na + Cl − Na + Cl −
Cl −
Na
Cl
+
−
Cl −
Na +
Cl
−
Cl
Na
+
−
Cl
−
Na +
Na +
Cl −
+
Na +
Na
(a) Interstitial defect (b) Schottky defect
(c) Frenkel defect (d) Frenkel and Schottky defects
28. The coordination number of a metal crystallizing in a hexagonal close packed structure is
(a) 4
(b) 12
(c) 8
(d) 6
29. In CsCl structure, the coordination number of Cs + is
(a) Equal to that of Cl − , that is 6
(b) Equal to that of Cl − , that is 8
(c) Not equal to that of Cl − , that is 6
(d) Not equal to that of Cl − , that is 8
30. Bragg's law is given by the equatio
equation
(a) n λ = 2θ sin θ
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(b) n λ = 2dd sin θ
(c)
2n λ = d sin θ
(d)
n
θ
2
=
d
sin θ
2
Chemistry
ANSWERS
5. (d)
6. (d)
7. (c)
8. (a)
9. (a)
1. (c) 2. (c) 3. (b)
4. (d)
11. (d) 12. (c) 13. (c)
14. (a)
15. (b)
16. (a)
17. (a)
18. (b)
19. (d)
21. (c) 22. (d) 23. (c)
24. (b)
25. (c)
26. (b)
27. (b)
28. (b)
29. (b)
Solutions
1. (c) Diamond is a covalent solid in which constituent particles are atoms.
2.(c)
For tetrahedral arrangement co
co-ordination number is 4 and radius ratio (r+ / r− ) is 0 .225 − 0 .414 .
3. (b) ρ =
=
4.
5.
6.
7.
10. (d)
20. (c)
30. (b)
n×M
a 3 × N 0 × 10 − 30
2 × 100
= 5 .188 g/cm 3
(400 )3 × (6 . 02 × 10 23 ) × 10 − 30
(d) In NaCl crystal every Na + ion is surrounded by 6 Cl − ion and every chloride ion is surrounded by 6 Na + ion.
(d) Schottky defect is due to missing of equal number of cations and anions.
(c) AgBr exhibits Frenkel defect due to large difference in the size of Ag + and Br − ions.
(c) When cation shifts from lattice to interstitial site, the defect is called Frenkel defect.
8. (a) A atoms are at eight corners of the cube. Therefore, the number of A atoms in the unit cell =
8
= 1 , atoms B per
8
unit cell = 1. Hence the formula is AB.
9. (a) M =
ρ × a 3 × N 0 × 10 −30
z
10 × (100 ) × (6 . 02 × 10 23 ) × 10 −30
= 15 . 05
4
3
=
23
No. of atoms in 100 g = 6.02 × 10 × 100 = 4 × 10 25 .
15.05
10. (d) Face centred cubic structure contribute of 1/8 by each atom present on the corner and 1/2 by each atom present
on the face.
11. (d) The bcc cell consists of 8 atoms at the corners and one atom at centre.
1
∴ n =  8 ×  + 1 = 2 .

8
The fcc cell consists of 8 atoms at the eight corners and one atom at each of the six faces. This atom at the face is
shared by two unit cells.
1
1
∴ n = 8 × +  6 ×  = 4 .
8

2
12. (c) A atoms are at eight corners of the cube. Therefore, the no. of A atoms in the unit cell =
face centre of six faces. Therefore, its share in the unit cell =
13. (c) Distance between centres of cation and anion =
8
= 1 . B atoms are at the
8
6
= 3 . The formula is AB3.
2
d 508
=
= 254 pm
2
2
rc + ra = 254 pm or 110 + ra = 254 or ra = 144 pm
14. (a) ZnS has zinc blende structure. It has cubic close packed (ccp) structure. The S2- ions are present at the corners of
the cube and at the centre of each face. Zinc ions occupy half of the tetrahedral sites. Each zinc ion is surrounded by four
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Chemistry
sulphide ions which are disposed towards the corners of a regular tetrahedron. Similarl
Similarly, S2- ion is surrounded by four Zn2+
ions.
15. (b) In fcc unit cell 4
√2 [r = radius of Cu atom a = edge length]
So,
√
⇒
√
127!".
4
16. (a) For CCP √2
√
2 (2R=diameter)
Diameter = 288.5
18. (b) There are 14 Bravais lattices (space lattices).
20. (c) SC a = 2r
BCC√3a = 4r
21.(c)
Metallic crystals are good conductor of heat and current due to free electrons in them.
22. (d) A
B
8
5
Formulla of compound A2B5.
23. (c) For FCC or CCP
4r = √2
P.F.
4;
2√2
P.F.
√
P.F. = 74%
Free space = 100-74=26%
24. (b) Body centered cubic lattice has a co
co-ordination number 8.
25. (c) CsBr3 consist of Cs + and Br3− ions.
26. (b) In this diagram, equal number of cations ( Na + ) and anions (Cl − ) are missing, so it, shows schottky defect.
27.
O-
Si
O-
OO-
28.
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Chemistry
(b) In hcp, co-ordination
ordination no. is 12.
29.
(b)
Cl − ions in CsCl
adopt BCC type of packing.
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