Solid state assignment and Quick revision notes
Before Solving the solid state assignment we are providing quick revision notes in form of tables.
1. What is semiconductor? Describe two main type of semiconductor and explain mechanism of their conduction.
2. What is the total no. of unit cell in a face centered cubic (fcc) structure?
3. What type of substance exhibit anti ferromagnetism?
4. How would You account for the following fact
i) Frenkel defect are not found in alkali metal halide.
ii) Schottky defect lower the density of related solid.
iii) Impurity doped silicon is a semiconductor.
5. Explain the following properties giving suitable example:-
i) Ferromagnetism
ii) Paramagnetism
iii) Ferrimagnetism
6. What is the co-ordination number of each ion in a rock salt type structure?
7. Which point defect in crystal does not alter the density of relevant solid?
8. Which point defect in its crystal unit increases the density of a solid?
9. How do metallic and ionic solid differ in conducting electricity
10. The density of copper metal is 9.95 gcm-3 .If the radius of copper atom be 127.8 pm. Is the copper unit cell is simple cubic , body centered cubic, or face centered cubic ?
11. What type of semiconductor id obtained when Silicon is doped with Arsenic?
12. Which point defect does not alter the density of solid?
13. What is a distinguish feature of metallic solid?
14. Chromium metal crystalize in a body centered cubic lattice. The length of unit unit cell edge is found to be 287 pm. Calculate the atomic radius of chromium.
15. Give one example of ionic solid which shows Frenkel defect.
16. Copper crystallizes in a fcc lattice and has density of 8.930 gcm-3 at 293K calculate the radius of copper atom . Cu = 63.55, NA= 6.602 x 1023 per mol.
17. Crystalline solid are anisotropic. What does this statement meant?
18. Calculate the packing efficiency of a metal crystal for a simple cubic lattice.
19. Explain how you can determine the atomic mass of a unknown solid if you know its mass, density and the dimension of unit cell of its crystal.
20. An alloy of gold and cadmium crystallizes with cubic structure in which gold atom occupies the corner and cadmium atoms fit into the face centered. Assign the formula for this alloy.
21. What is meant by ‘doping’ in a semiconductor?
22. How may the conductivity of an intrinsic semiconductor be increased?
23. What is n-type semiconductor?
24. What type of defect can arise when a solid is heated?
25. Why does ZnO acquire pink colour when heated?
26. What type of semiconductor is obtained when silicon is doped with boron?
27. What type of point defect is produced when AgCl is doped with CdCl2?
28. What type of substance would make better permanent magnet ferromagnetic or ferromagnetic?
29. What type of stoichiometric defect is shown by AgBr and AgI?
30. Account for the following:-
i) Schottky defect lower the density of related solid
ii) Conductivity of silicon increases on doping it with P
31. On heating a crystal of KCl in potassium vapors, the crystal starts exhibiting a violet colour. What is this due to?
32. How would you distinguish between the following pair of term
i) Tetrahedral and octahedral void
ii) Crystal lattice and unit cell
33. What do you mean by 12-16 and 13-15 compound
34. Write a short note on :- (i) Bravais lattice (ii)Pyro electric solids and (iii) F- centers (iv) piezoelectric solid
35. What is forbidden zone and doping
36. Which is the symmetric and asymmetric unit cell?
NUMERICALS
1. Voids and formula of compound:-
Remember:-
üAnion always present in packing
üCations always occupy the voids
üNumber of particles in packing (n) = no. of octahedral voids
üNumber of tetrahedral voids = 2x no. of octahedral void
37. In chromium (iii) CrCl3, the chloride ions have ccp arrangement. Cr 3+ ions are present in the octahedral voids. What fraction of octahedral void, tetrahedral void and total voids are occupied?
38. In compound atoms of element Y form ccp lattice and those of elements X occupy 2/3rd of tetrahedral voids. What will be the simplest formula of the compound?
39. In crystalline solid anions ‘C’ is arranged in ccp. Cation ‘A’ occupies 50% of the tetrahedral voids and Cations ‘B’ occupy 50% of octahedral voids. What is the formula of the solid?
40. In a solid oxide ions (O-2) are arranged in ccp. Cations A3+ occupy one sixth of the tetrahedral void and cations B3+occupy one third of the octahedral voids. What is the formula of the compound?
41. A solid is made of two elements P and Q. Atoms Q are present in the ccp arrangement while atoms P occupy all the tetrahedral voids. What is the formula of the compounds?
42. How many octahedral voids are there in 1 mol of an element having ccp packed structure?
43. A compound is formed by two elements ‘M’ and ‘N’. The element N form ccp and atom of M occupy one third of tetrahedral voids. What is the formula of compound?
2. Radius ratio :-
44. The two ions A+ and B– have radii 88 and 200 pm respectively. In the close packed structure of the compound AB. Predict the co-ordination no of A?
45. In a compound AX, the radius of Cation A+ ion is 95 pm and that of X– ion is 181 pm. Predict the crystal structure of AX and the co-ordination number of each ion.
46. A solid AB has NaCl structure. If the radius of the Cation A+ion is 170 pm calculate the maximum possible value of radius of anion
3. Density :-
47. Edge length of unit cell of NaCl crystal lattice is 5.6 Å. The density is 2.2 gcm-3. find the number of formula unit of NaCl per unit cell.
48. Lead sulphate crystal has NaCl structure. What is its density? The edge length of unit cell of PbS crystal is 500 pm. Given NA = 6.022*1023 , atomic mass Pb = 207.2 g mol –, S = 32 g mol–
49. An element crystalizes in a structure having a fcc unit cell of an edge length 200 pm. Calculate its density id 200g of this element contains 24 *10 23 atoms.
50. Calculate the Avogadro number from the following data
i) Density of NaCl is 2.165 g cm–
ii) Distance between Na+and Cl– in NaCl is 281 pm
Hint:- edge length(a) = 2 x (rNa+ + rCl-)
a = 2x 281 or a = 562 pm
51. KBr has NaCl type structure. What is the distance between K+ and Br– in KBr? If the density is 2.75 g/cm3.
52. Copper crystallizes into fcc lattice with edge length 3.361 x 10-8cm. show that the calculated density is in agreement with its mentioned value 8.92 g/cm3
53. Analysis shows that Nickel Oxide has formula Ni0.9801. what fraction exist as Ni2+ and Ni3+ ions?
4. Some NCERT QUESTIONS:-
54. What are poly crystalline solids?
55. What is the co-ordination no. in square close packing?
56. Calculate packing efficiency in :-
i) Simple cubic
ii) Body centered
iii) Face centered(Hexagonal close packed)
57. A compound forms a hexagonal close packed structure. What is the total number of voids in 0.5 mol of it? How many of these are tetrahedral voids?
58. Distinguish between :-
i) Hexagonal and monoclinic unit cell
ii) Face centered and end centered unit cell
59. Gold (atomic radius 0.144nm) crystallizes in a face centered unit cell. What is the length of the side of the cell?
60. Write two differences between isotropy and anisotropy
61. What are the differences between octahedral and tetrahedral voids?
62. What type of arrangement of layer in hcp and ccp packing?
63. Classify the following as amorphous and crystalline solid:-
Poythene, naphthalene, benzoic acid, Teflon, potassium nitrate, cellophane, polyvinyl chloride, fiber, glass, copper,
Why glass is considered a supercooled liquid?
64. Classify the following solid in different categories based on the nature of intermolecular forces operating in them:-
Potassium sulphate, tin, benzene, urea, ammonia, water, zinc sulphate, graphite, rubidium, argon, silicon carbide, AlN.
65. Solid ‘A’ is a very hard, electrical insulator in a solid as well as in molten state and melts at extremely high temperature. What type of solid is it?
66. Which network solid is an exceptionally good conductor of electricity?