The document consists of various chemistry questions related to crystal structures, unit cell dimensions, packing efficiency, and defects in solids. It covers calculations involving atomic radius, density, and formulas for compounds formed by different elements. Overall, it serves as a guide for students to understand solid-state chemistry concepts and problem-solving methods.

1. ROHIT RAJ RANJAN
my_chemistry@CBSE ROHIT RAJ RANJAN
Q.1. What is the formula of compound in which the elements Y form ccp lattice and atoms of X occupy2/3rd
of
octahedral voids.
Q.2. What is the formula of compound in which the elements Y form ccp lattice and atoms of X occupy1/3rd
of
tetrahedral voids.
Q.3. An ionic compound AB2 possesses CaF2 type crystal structure. Write the coordination number of A2+
and B-
ions in crystal AB2.
Q.4. Calculate the number of unit cell in 8.1 g of aluminium, if it crystallizes in a face centred cubic structure.
(atomic mass of Al=27 g.mol-1
)
Q.5. A compound forms hcp structure. What is the total number of voids in 0.5 mol of it. How many of these
are tetrahedral voids?
Q.6. An alloy of gold and cadmium crystallizes with a cubic structure in which gold atoms occupy the corners
and cadmium atoms fit into the face centres. Assign formula for this alloy.
#TOPIC : PACKING EFFICIENCY, CALCULATIONS INVOLVING UNIT CELL DIMENSION
Q.7. Express the relationship between atomic radius (r) and edge length (a) in fcc and bcc unit cell.
Q.8. Aluminium crystallizes in fcc structure atomic radius of metal is 125 pm. What is length of side of unit cell.
Q.9. What is the percentage efficiency of packing in case of simple cubic lattice.
Q.10. An elements with density 2.8 g.cm-3
forms a fcc unit cell with edge length 4 X 10-8
cm. calculate the molar
mass of the elements.
Q.11. The density of copper is 8.95 g.cm-3
forms a fcc unit cell, what is the radius of copper atom.(Cu=63.5)
Q.12. Iron has a body centred cubic unit cell with a cell dimension of 286.65pm. the density of iron is 7.874
g.cm-3
,use this information to calculate Avogadro’s number.(gram atomic mass of Fe=55.84 g.mol-1
)
Q.13. Silver crystallizes in face centred cubic unit cell. Each side of the unit cell has a length of 409pm.
What is the radius of silver atom.
Q.14. Cu crystallizes into fcc unit cell with edge length 3.61x10-8
cm. calculate the density of copper.
Q.15. Chromium crystallizes in bcc lattice. The length of the unit cell edge is found to be 287pm. Calculate the
atomic radius of chromium.
Q.16. An element crystallizes in a bcc lattice with cell edge of 500 pm. The density of the element is 7.5 g.cm-3
how many atoms are present in 300 g of the element.
Q.17. An element crystallizes in a Fcc lattice with cell edge of 250 pm. Calculate the density if 300 g of the this
element contains 2x 1024
atoms.
Q.18. An element with molar mass 27g.mol-1
form a cubic unit cell with edge length 4.05x10-8
cm. if its density
is 2.7 g.cm-3
,what is the nature of cubic unit cell.
Q.19. An element X (molar mass 27g.mol-1
) form a cubic unit cell with edge length 4.05x10-8
cm. if its density
is 6.23 g.cm-3
,what is the nature of cubic unit cell.
Q.20. Niobium crystallizes in bcc lattice, if its density is 8.55 g.cm-3
, Calculate the atomic radius of Niobium,
given its atomic mass is 934.
Q.21. an element occurs in bcc structure, it has a cell edge length of 250 pm. Calculate the molar mass if its
density is 8.0 g.cm-3
. Also calculate radius of atom of element.
Q.22. Silver crystallizes in fcc unit cell, If radius of silver atom is 145 pm, what is the length of each side.
Q.23. Tungsten crystallizes in bcc lattice. The length of the unit cell edge is found to be 316.5 pm. Calculate the
atomic radius of Tungsten.
Q.24. An element X crystallizes in a fcc lattice. if 208 g of the this element contains 4.2832x1024
atoms,
Calculate the edge of unit cell if density of X is 7.2 g.cm-3
.
Q.25. Lead crystallizes in fcc unit cell,if density of lead is 11.35 g.cm-3
,estimate the radius of lead atom
(at.mass of lead=297 g.mol-1
NA=6.023X1023
mol-1
)
Q.26. An element has a body centred cubic (bcc) structure with a cell edge of 288 pm. The density of the
element is 7.2 g/cm3
. How many atoms are present in 208 g of the element?
Q.27. A compound formed by elements X & Y, Crystallizes in the cubic structure, where X is at the corners of
the cube and Y is at the six face centers. What is the formula of the compound? If side length is 5A°,
estimate the density of the solid assuming atomic weight of X and Y as 60 and 90 respectively.
SOLID STATE

2. Q.28. A compound formed by elements X and Y has cubic unit cells in which X – atoms are at the corners of the
cube and Y – atoms are at the face centre. What is the formula of the compound? If the atomic weight of
X and Y are 10 and 15 respectively, then find out the no of unit cell present in 20 gm of compound.
Q.29. aluminium crystallizes in cubic closed packed unit cell radius of the atom in the metal is 125 pm
(a) what is the length of side of the unit cell (b) how many unit cell are there in 1cm3
of aluminium.
Q.30. a well known mineral fluorite is chemically calcium fluorite. It is known that in one unit cell of this mineral
There are 4 Ca2+
ion and 8F-
ion and that Ca2+
ion are arrange in in fcc lattice. The F-
ions fill all
tetrahedral holes in the fcc lattice of Ca2+
ions. The edge of the unit cell cell is 5.46x10-8
cm in length. The
density of solid is 3.18 g.cm-3
. Use this information to calculate the Avogadro’s number.
(molar massof CaF2=78.08 g.mol-1
)
Q.31. A solid AB has CsCl type structure. The edge length of the unit cell is 404 pm. Calculate the distance of
closest approach between A+
and B-
ions.
#TOPIC : IMPERFECTION IN SOLID, ELECTRICAL & MAGNETIC PROPERTIES
Q.32. What type of magnetism is shown by substance if magnetic moments of domains are arranged in same
direction -or- write the type of magnetism observed when the magnetic moments are aligned in parallel
and anti-parallel direction in unequal number.
Q.33. What type of stoichiometric effect is shown by AgCl, NaCl, AgI
Q.34. What type of substances would make better permanent magnets, ferromagnetic or ferromagnetic?
Q.35. What is meant by the term forbidden zone in reference to band theory of solids?
Q.36. Why is Frenkle defect not found in pure alkali metal halide?
Q.37. What are the F-centres.
Q.38. What type of magnetism is shown by substance if magnetic moments of domains are arranged in
opposite direction and cancel out each other.
Q.39. Examine the given defective crystal
A+
B-
A+
B-
A+
B-
B-
A+
B-
A+
B-
A+
A+
B-
A+
B-
A+
B-
I) What type of stoichiometric defect is shown by the crystal
II) How is the density of affected by this defect?
III) what type of ionic substances show such defect?
Q.40. What type of non-stoichiometric point defect is responsible for the pink color of LiCl.
Q.41. Why does the presence of excess of lithium makes LiCl crystal pink?
Q.42. What changes occurs when AgCl is doped with CdCl2.
Q.43. If NaCl is doped with 10-3
mole per sec SrCl2, what will be the concentration of cation vacancies.
Q.44. Based on the nature of intermolecular forces classify the silicon, carbide, argon.
Q.45. ZnO turns yellow on heating, why?
Q.46. What is meant by group 12-16 compounds? Give an example.
Q.47. Account for the following :
I. Fe3O4 is ferrimagnetic at room temperature buit becomes paramagnetic at 850 K.
II. Schottky defect lowers the density of related solid.
Q.48. A metal crystallizes in FCC unit cell with a=0.560nm. calculate the density of meta if it contains 0,1%
Schottky defect. (at. Mass of metal=40 g.mol-1
)
Q.49. If NaCl is doped with 10-3
mole% SrCl2 what is the concentration of cation vacancies?
Q.50. A metal crystallizes into two cubic system-face centred cubic (fcc) and body centred cubic (bcc) whose
unit cell lengths are 3.5 and 3.0Å respectively. Calculate the ratio of densities of fcc and bcc.
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