THE SOLID STATE
CMP
ONE MARK OUESTIONS
1
A compound contains two types of atoms X and Y.It crystallizes in a cubic lattice with atom X at
the corners of the unit cell and atoms Y at the body centre.What is the simplest possible formula
of the compound?
2.
Window glass/ glass objects of old buildings look milky.Why?
3.
Glass panes fixed to windows or door of old buildings are found to be thicker at bottom.Why?
4.
How many octahedral and tetrahedral voids are there in one mole of a compound having ccp
structure?
5.
Name the non-stoichiometric point defect responsible for colour in alkali halides?
6.
What makes the crystals of KCl appear violet?
7.
What is the effect of schottky and frenkel defects on the density of crystalline solids?
8.
9.
What type of stoichiometric defect is shown by –
(1) ZnS and (2) CsCl
(1)
Name one solid in which both frenkel and schottky defects occur?
10.
Why is frenkel defect found in AgCl?
11.
What type of crystal defect is produced when CdCl2 is doped with AgCl ?
12.
13.
Classify each of the following as being either a p-type or n-type semiconductor?
(1) Ge doped with In
(2) B doped with Si
(1)
What is a coordination number of each type of ions in a rock salt type crystal structure?
14.
How can a ferromagnetic substance be changed to paramagnetic one ?
15.
What type of substances exhibits antiferromagnetism ?
1.
TWO MARKS QUESTIONS
Write four differences between schottky and frenkel defects/
2.
A compound is formed by two elements A and B.Elements B forms ccp and a occupy 1/3rd of
tetrahedral voids.what is the formula?
3.
Copper crystallizes into fcc lattice with edge length 3.61 x 10 -8 cm.Show that the calculated
density is in agreement with its measured value of 8.92 cm-3.
4.
Gold (atomic radius = 0.144 nm) crystallizes in a fcc .what is the length of the side of the cell?
5.
The length of unit cell edge of a bcc metal crystal is 352 pm.Calculate the radius of an atom of a
metal.
6.
Define the following with examples.
i.
12-16 compounds
ii.
13-15 compounds.
7.
Define the following :(i)diamagnetic and (ii)paramagnetic
8.
Classify the following solids as ionic,molecular,metallic,amorphous and covalent solids
1)LiBr 2) Brass 3) Iodine 4) Plastic 5) graphite 6) Phosphorus
9
Differenciate between n-ype and p-type semiconductors.
10
If NaCl is doped with 10 -3 mol % SrCl 2, what is the concentration of Cation Vacancy?
11
Refractive index of a solid is observed to have the same value along all directions. Comment on
the nature of this solid. Would it show cleavage property? Give an example of this type of Solid.
HOTS
1 mark Questions
1
Classify each of following as either p-type or n-type semiconductor:
1) Ge doped with In 2) B doped with Si
2
Why is Frenkel defect found in AgCl.
3
On heating Crystals of KCl in potassium vapours the crystal start exhibiting a violet color.
4
Why is frenkel defect not found in Pure alkali metals halides?
5
Give an example of a solid in which the ratio of the co-ordination no. of cation and anion is
4:8
6
How many effective Sodium ions are located at the edge centre of a unit cell in NaCl Crystal?
7
Name the non-stoichiometric defect responsible for color in alkalihalides.
8
What type of packing results when a lattice contains a sequence of layers of ABCABC? What
is co-ordination no. of each atom in same layer?.
9
Why does the conductivity of metals decreases when temperature is increased?
10
At what temp. range do most of the metals become superconductors?
11
In Corundum, oxide ions are arranged in hcp and Al ions occupy 2/3 of the octahedral voids.
What is formula of the compound?
12
Why is window glass of old buildings thick at the bottom?
2 mark Questions
1
Analysis shows that Nickel oxide has the formula Ni0.98O . What fraction of the Nickel exists
as Ni 2+ and Ni 3+ions.
2
If the radius of the octahedral void is r and the radius of the atoms in the close packing is R,
derive relationship between r and R.
3 mark Questions
1
Aluminium crystallizes in a cubic close packed structure. Its metallic radius is 125pm.
(a) What is the length of the side of the unit cell?
(b) How many unit cells are there in 1.00cm3 of Aluminium?
2
An element crystallizes in FCC structure; 200 g of this element has 2.408 x 10
24atoms. If the density of A is 7.2 g per cc, calculate the edge length of unit cell.
3
Niobium Crystallise in BCC structure. If the density is 8.55 g per cc. Calculate atomic radius of
Niobium. Given that its atomic mass is 93 u.