GITARATTAN JINDAL PUBLIC SCHOOL
ROHINI, DELHI-110085
QUESTION BANK
SOLID STATE
CLASS
: XII
SUBJECT : Chemistry
(1 Mark)
Q1.
Q1 (a)
What is meant by an “intrinsic semiconductor”?
What is the Co-ordination number of each type of ions in a rock-salt type crystal structure?
Q2.
Define the term anisotropic and isotropic.
Q3.
What is the total number of atoms per unit cell in fcc structure?
Q4.
What type of substances exhibits antiferromagnetism?
Q5.
What type of alignment in crystals makes them ferromagnetic?
Q6.
Which point defect in crystals does not alter the density of the relevant solid?
Q7.
Which point defect in crystal increase the density of the solid? (Intersteliat defect)
Q8.
How do metallic and ionic substances differ in conducting electicity?
Q9.
What is the number of atoms in a body – centred cubic unit cell of a crystal?
Q10.
What type of interaction hold the molecules together in a polar molecular solid?
Q11.
What type of semiconductor is obtained when ‘Si’ is doped with assemic?
Q12.
Give an example of an ionic compound which shows Frenkel defect?
Q13.
What is the number of atoms in simple cubic unit cell of a crystal?
Q1.
What is a semiconductor? Describe the two main types of semiconductors and explain mechanisms for
their conduction.
Q2.
How would you account for the following:
(i) Frenkel defect is not found in alkali metal halides.
(ii) Schottky defects lower the density of related solids.
(iii) Impurity doped silicon is a semiconductor.
Q3.
Q4.
Explain the following properties giving suitable examples.
(i) Ferromagnetism
(ii) Paramagnetism
(iv) F-centres
(v) Frankel defects
(iii) Ferrimagentism
Silver crystallizes in an fcc lattice. The edge length of its unit cell is 4.077 x 10-8 cm and its density is
10.5 g/cm3. Calculate atomic mass of silver (NA = 6.02 x 1023 mol-1)
Q5.
Iron has body centred cubic unit cell with a cell edge of 286.65 pm. The density of iron is 7.87 g/cm3.
Calculate Avagadro number (At. Mass of Fe = 56 g/mol) (2 times)
Q6.
Silver crystallises with face-centred cubic unit cell. Each side of the unit cell has a length of 409 pm. What
is the radius of an atom of silver.
Q7.
A well known mineral fluorite is chemically calcium fluoride. It is known that in one unit cell of this
mineral there are 4 Cu+2 ions and 8 F- ions and that Ca+2 ions are arranged in a fcc lallice. The fluoride ions
fill all tetrahedral holes in the fcc of Ca+2 ions. The edge length of the unit cell is 5.46 X 10-8 cm in length.
The density of the solid is 3.18 g/km3. Calculate Avagadro number.
Q8.
The density of copper metal is 8.95 g/cm3. If the radius of copper atom is 127.8 pm, is the copper unit cell
a simple cubic, a body – centred cubic or a face – centred cubic structure? (At. Mass of Cu = 63.5 g/mol
NA = 6.02 x 1023)
Q9.
Copper crystallizes into an fcc lattice with edge length 3.61 x 10-8 cm. Calculate the density of copper.
Q10.
Copper crystallizes in face – centred cubic lattice and has density of 8.9 g./cm3 at 293 k. Calculate the
radius of copper atom.
Q11.
Explain how you can determine the atomic mass of an unknown metal if you know its mass, density and
the dimension and type of unit cell of its crystal.
Q12.
Calculate the packing efficiency of a metal crystal for a simplic cubic lattice.
Q13.
Aluminium crystallises in a cubic close packed structure. Radius of the atom in the metal is 125 pm.
(i) What is the length of the unit cell?
(ii) How many unit cells are there in 1 cm3 of aluminium?
Q14.
Name an element in its ion form when doped in AgCl causes cation vacancy.
Q15.
Name the non – stoichiometric point defect responsible for colour in alkalihalides.
Q16.
Copper is conducting as such while copper sulphate is conducting only in molten state?
Q17.
What happens when ferrimagentic Fe3O4 is heated at 850 K and why?
Q18.
Why is Frenkel defect found in AgCl?
Q19.
In an alloy of gold and Cadmium, gold crystallizes in cubic structure occupying the corners only and ‘cd’
fits into the face centre voids. What is quantitative composition of the alloy?
Q20.
A compound is formed by two elements M and N. The element N for CCP and atoms of M occupy 1/3rd of
tetrahedral Voids. What is the formula of the compound?
Q21.
Why ZnO crystals appears yellow on heating?
Q22.
Stalility of a crystal is reflected in the magnitude of its melting point? Comment.
Q23.
What is meant by ‘doping’ in a semiconductor?