#### Solid State Model Question Paper

12th Standard EM

Reg.No. :
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Chemistry

Time : 02:00:00 Hrs
Total Marks : 50
10 x 1 = 10
1. An ionic compound AxBy crystallizes in fcc type crystal structure with B ions at the centre of each face and A ion occupying entre of the cube. the correct formula of AxBy is

(a)

AB

(b)

AB3

(c)

A3B

(d)

A8B6

2. In calcium fluoride, having the flurite structure the coordination number of Ca2+ ion and F- Ion are (NEET)

(a)

4 and 2

(b)

6 and 6

(c)

8 and 4

(d)

4 and 8

3. The number of carbon atoms per unit cell of diamond is

(a)

8

(b)

6

(c)

1

(d)

4

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)

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

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

(a)

488.5pm

(b)

848.5pm

(c)

884.5pm

(d)

484.5pm

6. Schottky defect in a crystal is observed when

(a)

unequal number of anions and anions are missing from the lattice

(b)

equal number of anions 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

7. The crystal with a metal deficiency defect is

(a)

NaCl

(b)

FeO

(c)

ZnO

(d)

KCl

8. In which of the following arrangements, octahedral voids are formed?

(a)

fcc

(b)

bcc

(c)

simple cubic

(d)

hcp

9. What is the relation between diamond and .graphite?

(a)

Polymorphous

(b)

Isomer

(c)

Isotope

(d)

Isomorphous

10. A regular three dimensional arrangement of identical points in space is called

(a)

Unit cell

(b)

Space lattice

(c)

Primitive

(d)

Crystallography

11. 5 x 1 = 5
12. Impurity defect

13. (1)

NaCl with Sr2+ and some cationic sites vacant.

14. Metal deficiency defect

15. (2)

NaCI

16. Schottky defect

17. (3)

FeO with Fe3+

18. Schottky defect

19. (4)

NaCI

20. Monoclinic

21. (5)

a≠b≠c, ∝=૪=90o, β≠90o

5 x 2 = 10
22. Define unit cell

23. Give any three characteristics of ionic crystals.

24. Explain briefly seven types of unit cell

25. Distinguish tetrahedral and octahedral voids.

26. What are point defects?

27. 5 x 3 = 15
28. Explain Schottky defect.

29. Calculate the number of atoms in a fcc unit cell

30. Why ionic crystals are hard and brittle?

31. Calculate the percentage efficiency of packing in case of body centered cubic crystal.

32. What is the two dimensional coordination number of a molecule in square close packed layer?

33. 2 x 5 = 10
34. if NaCl is doped with 10-2 mol percentage of strontium chloride, what is the concentration of cation vacancy

35. Atoms X and Y form bcc crystalline structure. Atom X is present at the corners of the cube and Y is at the centre of the cube. What is the formula of the compound?