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 cm$$^{-3}$$) 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 $$90^o$$ 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\ \mathring A$$ and $$b = 7.60\ \mathring A$$ (see figure). How many molecules of water are contained in a given unit cell?  [Density of ice is $$0.92$$ g cm$$^{-3}$$.]
264608_f5c9a35b893f478087d2b8bd8f6cfae1.png
  • $$2$$
  • $$3$$
  • $$4$$
  • $$5$$
Potassium crystallizes in a body-centered cubic lattice with edge length aequal to 5.2 $$\mathring A$$ , what is the calculated density (in g cm$$^{-3}$$) of crystalline potassium ?
  • $$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$$ pm, compute the density (in g cm$$^{-3}$$) of iron in bcc and fcc respectively :
  • $$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$$ nm. What is the density (in g cm$$^{-3}$$) of sodium chloride?
  • $$1.5$$
  • $$2.0$$
  • $$2.2$$
  • $$3.2$$
Pyrite, $$FeS_2$$ crystallises in a cubic unit cell with a cell edge of 0.54 nm. The density of pyrite is $$5.02 g/cm^3$$. How many $$Fe^{2+}$$ and $$S^{2-}_2$$ ions are present in a single unit cell?
(S = 32, Fe =56u)
  • $$1 Fe^{2+}$$ and $$1 S^{2-}_2$$
  • $$2 Fe^{2+}$$ and $$2 S^{2-}_2$$
  • $$4 Fe^{2+}$$ and $$4 S^{2-}_2$$
  • $$6 Fe^{2+}$$ and $$6 S^{2-}_2$$
A compound having bcc geometry has atomic mass $$50$$ amu. Calculate the density (in g cm$$^{-3}$$) of the unit cell, if its edge length is $$290$$ pm.
  • $$6.81$$
  • $$3.40$$
  • $$13.62$$
  • None of the above
The most unsymmetrical crystal system is:
  • cubic
  • hexagonal
  • triclinic
  • orthorhombic
A pseudo solid is:
  • glass
  • pitch
  • KCl
  • glass and pitch both
The lattice parameters, $$a\neq b\neq c$$ and $$\alpha\neq\beta\neq\gamma\neq 90^{\circ}$$ represents a__________.
  • tetragonal system
  • orthorhombic system
  • monoclinic system
  • triclinic system
In a simple cubic cell, each point on a corner is shared by:
  • 2 unit cells
  • 1 unit cell
  • 8 unit cells
  • 4 unit cells
Which of the following are the correct axial distances and axial angles for rhombohedral system?
  • $$\;a=b=c,\,\alpha=\beta=\gamma\neq 90^{\circ}$$
  • $$\;a=b\neq c,\;\alpha=\beta=\gamma=90^{\circ}$$
  • $$\;a\neq b=c,\;\alpha=\beta=\gamma=90^{\circ}$$
  • $$\;a\neq b\neq c,\;\alpha\neq\beta\neq\gamma\neq 90^{\circ}$$
Close packing is maximum in the crystal lattice of:
  • simple cubic
  • face-centred
  • body-centred
  • hexagonal closed packing
The empty space in hcp and ccp is about :
  • $$26\%$$
  • $$30\%$$
  • $$35\%$$
  • $$40\%$$
For an orthorhombic system, axial ratios are $$a\neq b\neq c$$ and the axial angles are:
  • $$\;\alpha=\beta=\gamma\neq 90^{\circ}$$
  • $$\;\alpha=\beta=\gamma=90^{\circ}$$
  • $$\;\alpha\neq \beta=\gamma=90^{\circ}$$
  • $$\;\alpha\neq\beta\neq\gamma=90^{\circ}$$
Which of the following is a primitive unit cell?
  • Simple cubic
  • Body-centred cubic
  • Face-centred cubic
  • Both body-centred and face-centred cubic
A tetrahedral void in a crystal implies that:
  • the shape of the void is tetrahedral
  • molecules forming the void are tetrahedral in shape
  • the void is surrounded tetrahedrally by four spheres
  • the void is surrounded by six spheres
Which one of the following is not a close packing?
  • HCP
  • CCP
  • BCC
  • FCC
If the co-ordination number of an element in its crystal lattice is 8, then packing is :
  • fcc
  • hcp
  • bcc
  • none of the above
The number of octahedral sites in a cubical close packed array of $$N$$ spheres is :
  • $$\dfrac 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$$ pm. The density (in g cm$$^{-3}$$) of the element is:
  • $$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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