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CBSE Questions for Class 12 Engineering Chemistry The Solid State Quiz 7 - MCQExams.com

Which of the following statements is/are correct about tetrahedral voids (TVs) in an fcc unit cell ?
  • Number of TVs per atom in fcc unit cell is 2.
  • Number of TVs per unit cell is 8.
  • Number of TVs is twice the number of atoms in the fcc unit cell.
  • Number of TVs is equal to the number of atoms in the fcc unit cell.
Statement: The maximum number of Bravais lattices is shown by tetragonal type crystals.

State whether the given statement is true or false.
  • True
  • False
Which one of the following schemes of ordering closed packed sheets of equal sized spheres do not generate close packed lattice?
  • ABCABC
  • ABACABAC
  • ABBAABBA
  • ABCBCABCBC
The empty space left in hcp in three dimensions is :
  • 26%
  • 74%
  • 52.4%
  • 80%
Chromium metal crystallizes as a body-centered cubic lattice. The length of the unit cell edge is found to be 287 pm. What would be the density (in g cm3) of chromium?
  • 3.40
  • 5.20
  • 12.10
  • 7.30
Assertion (A): Triclinic system is the most unsymmetrical system.
Reason (R): No axial angle is equal to 90o in the triclinic system.

Choose the correct option.
  • Both (A) and (R) are correct and (R) is the correct explanation of (A)
  • Both (A) and (R) are correct but (R) is not the correct explanation of (A)
  • (A) is correct but (R) is incorrect
  • (A) is incorrect but (R) is correct
  • Both (A) and (R) are incorrect
Statement: Packing fraction of a lattice structure depends on the radius of the atom crystallizing in it.

State whether the given statement is true or false.
  • True
  • False
Statement: It is much more difficult to describe the crystal structure of compounds than those of elements.

State whether the given statement is true or false.
  • True
  • False
Which of the following is not a crystalline solid?
  • Common salt
  • Sugar
  • Iron
  • Rubber
KF has a NaCl structure. What is the distance (in pm) between K+ and F in KF if the density is 2.48 g cm$$^{-3}?
  • 220
  • 135
  • 540
  • 269
Which of the following is an amorphous substance?
  • Zinc
  • Clay
  • Salt
  • Sugar
Ice crystallizes in a hexagonal lattice. At low temperature, at which the structure was determined, the lattice constants were a=4.53 ˚A and b=7.60 ˚A (see figure). How many molecules of water are contained in a given unit cell?  [Density of ice is 0.92 g cm3.]
264608_f5c9a35b893f478087d2b8bd8f6cfae1.png
  • 2
  • 3
  • 4
  • 5
Potassium crystallizes in a body-centered cubic lattice with edge length aequal to 5.2 ˚A , what is the calculated density (in g cm3) of crystalline potassium ?
  • 2.2
  • 1.9
  • 0.92
  • None of the above
Iron occurs as bcc as well as fcc unit cell. If the effective radius of an atom of iron is 124 pm, compute the density (in g cm3) of iron in bcc and fcc respectively :
  • 8.4, 9.8
  • 9.3, 4.6
  • 8.6, 7.9
  • 7.9, 8.6
A unit cell of sodium chloride has four formula units. The edge of length of the unit cell is 0.564 nm. What is the density (in g cm3) of sodium chloride?
  • 1.5
  • 2.0
  • 2.2
  • 3.2
Pyrite, FeS2 crystallises in a cubic unit cell with a cell edge of 0.54 nm. The density of pyrite is 5.02g/cm3. How many Fe2+ and S22 ions are present in a single unit cell?
(S = 32, Fe =56u)
  • 1Fe2+ and 1S22
  • 2Fe2+ and 2S22
  • 4Fe2+ and 4S22
  • 6Fe2+ and 6S22
A compound having bcc geometry has atomic mass 50 amu. Calculate the density (in g cm3) of the unit cell, if its edge length is 290 pm.
  • 6.81
  • 3.40
  • 13.62
  • None of the above
The most unsymmetrical crystal system is:
  • cubic
  • hexagonal
  • triclinic
  • orthorhombic
A pseudo solid is:
  • glass
  • pitch
  • KCl
  • glass and pitch both
The lattice parameters, abc and αβγ90 represents a__________.
  • tetragonal system
  • orthorhombic system
  • monoclinic system
  • triclinic system
In a simple cubic cell, each point on a corner is shared by:
  • 2 unit cells
  • 1 unit cell
  • 8 unit cells
  • 4 unit cells
Which of the following are the correct axial distances and axial angles for rhombohedral system?
  • a=b=c,α=β=γ90
  • a=bc,α=β=γ=90
  • ab=c,α=β=γ=90
  • abc,αβγ90
Close packing is maximum in the crystal lattice of:
  • simple cubic
  • face-centred
  • body-centred
  • hexagonal closed packing
The empty space in hcp and ccp is about :
  • 26%
  • 30%
  • 35%
  • 40%
For an orthorhombic system, axial ratios are abc and the axial angles are:
  • α=β=γ90
  • α=β=γ=90
  • αβ=γ=90
  • αβγ=90
Which of the following is a primitive unit cell?
  • Simple cubic
  • Body-centred cubic
  • Face-centred cubic
  • Both body-centred and face-centred cubic
A tetrahedral void in a crystal implies that:
  • the shape of the void is tetrahedral
  • molecules forming the void are tetrahedral in shape
  • the void is surrounded tetrahedrally by four spheres
  • the void is surrounded by six spheres
Which one of the following is not a close packing?
  • HCP
  • CCP
  • BCC
  • FCC
If the co-ordination number of an element in its crystal lattice is 8, then packing is :
  • fcc
  • hcp
  • bcc
  • none of the above
The number of octahedral sites in a cubical close packed array of N spheres is :
  • N2
  • 2N
  • N
  • 4N
At zero kelvin, most of the ionic crystals possess :
  • Frenkel defect
  • Schottky defect
  • metal excess defect
  • No defect
An element (atomic mass =100 g/mol) having bcc structure has unit cell edge length 400 pm. The density (in g cm3) of the element is:
  • 10.376
  • 5.188
  • 7.289
  • 2.144
The available space occupied by spheres of equal size in three dimensions in both hcp and ccp arrangement is:
  • 74 %
  • 70 %
  • 60.4 %
  • 52.4 %
A truncated tetrahedron has_______________.
  • 12 vertices
  • 8 faces
  • 18 edges
  • 3 hexagonal faces
Solid sodium amide, NaNH_2 has a cubic closed packed arrangement of N{ H }_2^- ions with _____ voids occupied by Na^+ ions.
  • half the number of octahedral
  • all tetrahedral
  • half the number of tetrahedral
  • double the number of octahedral
An element crystallizes in a structure having a fcc unit cell with edge length 200 pm. Calculate its density (in g cm^{-3}) if 200 g of this element contain 24\times10^{23} atoms.
  • 10.4
  • 2.6
  • 41.6
  • 83.2
The more efficient mode of packing of identical atoms in one layer is :
  • square close packing pattern
  • hexagonal close packing pattern
  • trigonal closed packing
  • none of the above
A metallic crystal crystallizes into a lattice containing a sequence of layers AB AB AB.... . Any packing of spheres leaves out voids in the lattice. What percentage of the volume of this lattice is empty space?
  • \;74\%
  • \;26\%
  • \;50\%
  • \;33\%
Crystal system in which maximum number of Bravais lattices are possible is:
  • cubic
  • triclinic
  • orthorhombic
  • rhombohedral
The maximum proportion of available volume that can be filled by hard spheres in diamond is:
  • 0.52
  • 0.34
  • 0.32
  • 0.68
Which crystal system does the unit cell dimensions, a\neq b\neq c and \alpha= \beta= \gamma represent?
  • Cubic
  • Orthorhombic
  • Tetragonal
  • Trigonal
The ABAB packing and ABCABC packing are respectively called as:
  • hexagonal close packing (hcp) and cubic close packing (ccp)
  • cubic closed packing (ccp) and hexagonal closed packing (hcp)
  • body centered cubic (bcc) and hexagonal close packing (hcp)
  • hexagonal closed packing (hcp) and body-centered cubic (bcc)
Tetragonal crystal system has which of the following unit cell dimensions?
  • a = b = c and \alpha = \beta = \gamma = 90^{\circ}
  • a = b \neq c and \alpha = \beta = \gamma = 90^{\circ}
  • a \neq b \neq c and \alpha = \beta = \gamma = 90^{\circ}
  • a = b \neq c and \alpha = \beta = 90^{\circ}, \gamma = 120^{\circ}
ZnS can be existing in the ________ structure other than zing blende structure.
  • Bcc
  • Wurtzite
  • Simple cubic
  • Rock salt
Average composition of ordinary glass is:
  • Na_2O\cdot CaO\cdot 6SiO_2
  • Na_2O\cdot 2CaO\cdot 3SiO_2
  • Na_2O\cdot CaO\cdot 6SiO_2\cdot Cr_2O_3
  • Na_2O\cdot CaO\cdot PbO\cdot 6SiO_2
A compound AB has a rock type structure with A:B =1:1. The formula mass of AB is 6.023 y^{1/3} y amu and the closest A-B distance is y^{1/3} nm.Calculate the density of lattice.
  • 5.0 kg/m^3
  • 10 kg/m^3
  • 50kg/m^3
  • 20 kg/m^3
Pick out the crystalline substance from the following.
  • Coal
  • Wax
  • Clay
  • Sugar

Which of the following is an amorphous substance?

  • Zinc
  • Clay
  • Salt
  • Sugar
The space lattice of graphite is:
  • cubic
  • tetragonal
  • rhombic
  • hexagonal
Identify the crystalline solid among the following :
  • Glass
  • Carbon black
  • Resin
  • Silver
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