On the basis of unit cell concept a crystal has :
  •   7 systems
  •   14 systems
  •   230 systems
  •   32 systems

If NaCl is doped with 10-4 mol % of SrCl2, the concentration of cation vacancies will be

(NA = 6.023 x 1023 mol-1)                                                                             

  • 6.023 x 1015 mol-1             

  • 6.023 x 1016 mol-1

  • 6.023 x 1017 mol-1             

  • 6.023 x 1014 mol-1                                     

The phenomenon in which polar crystals on heating produce electricity is called:-

  • Pyro-electricity.

  • Piezo-electricity.
  • Ferro-electricity.
  • Ferri-electricity.

Total volume of atoms present in a face centred cubic unit cell of a metal is -

(r is atomic radius)

  • 20/3 πr3

  •   24/3 πr3

  •   12/3 πr3

  •   16/3 πr3

Lithium borohydride (LiBH4), crystallizes in an orthorhombic system with 4 molecules per unit cell. The unit cell dimensions are:- a = 6.81 Å , b = 4.43 Å ,c = 7.17 Å. If the molar mass of LiBH4 is 21.76 g mol-1.The density of the crystal is:-

  • 0.67 g cm-3

  • 0.58 g cm-3

  • 1.23 g cm-3

  • None of the above.

The arrangement of X- ions around A+ ion in solid AX is given in the figure (not drawn to scale).
If the radius of X-  is 250 pm, the radius of A+ is: 
  • 104 pm

  • 125 pm

  • 183 pm

  • 57 pm

In an f.c.c. unit cell. atoms are numbered as shown below. The atoms not touching each other are (Atom numbered 3 is face centre of front face).
  • 3&4

  • 1&3

  • 1&2

  • 2&4

A solid has a bcc structure. If the distance of closest approach between the two atoms is 1.73Å . The edge length of the cell is:

  • 200pm

  •  32 pm

  • 142.2 pm

  •  2pm

Which is covalent solid?

  • Silicate

  • Diamond

  • Graphite 

  • All of these

What type of crystal defects is indicated in the diagram given below?

  • Frenkel and Schottky defects

  • Schottky defect

  • Interstitial defect

  • Frenkel defect

The anions (A) form hexagonal closest packing and atoms (C) occupy only 2/3 of octahedral voids in
it. The general formula of the compound is-
  • CA
  • CA2
  • C2A3
  • C3A2

The mass of a unit cell of CsCl corresponds to:-
  • 8 Cs+ and Cl-
  • 1Cs+ and 6Cl-
  • 1Cs+ and 1Cl-
  • 4Cs+ and Cl-

Graphite in an example of-

  • Ionic solid

  • Covalent solid

  •  Molecular Solids

  • Metallic crystal

Which arrangement of electrons leads to anti-ferromagnetism?

  •   

  •   

  • Both (1) and (2)

  • None of the above.

The intermetallic compound LiAg has a cubic crystalline structure in which each Li atom has 8 nearest neighbour silver atoms and vice-versa. What is the type of unit cell?

  • Body centred cubic

  • Face centred cubic

  • Simple cubic for either Li atoms alone or Ag atoms alone

  • None of the above

The arrangement ABC ABC.. is referred to as.

  • octahedral close packing

  • hexagonal clase packing

  • tetrahedral close packing

  • cubic close packing

How many unit cells are present in a cube shaped ideal crystal of NaCl of mass 1.00g?

[ Atomic masses Na=23, Cl = 35.5]

  • 2.57 x 1021

  • 5.14 x 1021

  • 1.28 x 1021

  • 1.71 x 1021

The ratio of cations to anion in a closed pack tetrahedral is:
  • 0.714

  • 0.225

  • 0.02

  • none of these

The most efficient packing of similar spheres is obtained in 

  • The simple cubic system and the body centered cubic system

  • The simple cubic system and the hexagonal close packed system

  • The face centered cubic system and the hexagonal close packed system

  • The body centered cubic system and the face centered cubic system

In a compound, atoms of element Y form ccp lattice, and those of element X occupy 2/3rd of tetrahedral voids. The formula of the compound will be :-
  • X3Y4
  • X4Y3 
  • X2Y3
  • X2Y

A spinel is an important class of oxides consisting of two types of metal ions with the oxide ions arranged in ccp layers. The normal spinel has 1/8th of the tetrahedral void occupied  by one type of metal and one half of the octahedral voids occupied by another type of metal ions. Such a spinel is formed by Zn2+, Al3+ and O2- with Zn2+ in tetrahedral void. Give the simplest formula of the spinel.

  • ZnAl2O4

  • ZnAl2O3

  • ZnAlO

  • None of these

Close packing is maximum in the crystal lattice of:
  • simple cubic

  • face centred

  • body centred

  • none of these

Frenkel defect is noticed in:

  • AgBr

  • ZnS

  • Agl

  • All of the above

The density of KCl is 1.9893 g cm-3 and the length of a side unit cell is 6.29082 Å as

determined by X-ray diffraction. The value of Avogadro’s number calculated from these

data is:-
  • 6.017 x 1023

  • 6.023 x 1022

  • 7.03 x 1023

  • 6.01 x 1019

How many octahedral and tetrahedral holes are present per unit cell in a face centred cubic arrangement of atoms?

  • 8,4

  • 1,2

  • 4,8

  • 2 ,1

TiO2 is a well-known example of:

  • Triclinic system.

  • Tetragonal system.

  • Monoclinic system.

  • None of the above.

For a solid with the following structure, the co-ordination number of the point B is:

  • 3

  • 4

  • 5

  • 6

The elements of symmetry in a crystal are:-

  • Plane of symmetry

  • Axis of symmetry

  • Centre of symmetry

  • All of the above

Compute the percentage void space per unit volume of unit cell in zinc fluoride structure.

  • 15.03%

  • 22.18%

  • 18.23%

  • 25.07%

8 : 8 co-ordination of CsCl is found to change into 6 : 6 co-ordination on:
  • Applying pressure.

  • Increasing temperature.

  • Both 1 and 2.

  • None of these.

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