CBSE Class 12 Chemistry The Solid State MCQs

Question : Chottky defect defines imperfection in the lattice structure of

a) solid 
b) gas
c) liquid
d) plasma

Answer : A

Question : An AB₂ type structure is found in

a) NaCl  
b) CaF₂
c) Al₂O₃
d) N₂O

Answer : B

Question : An element (atomic mass 100 g/mol) having bcc structure has unit cell edge 400 pm. The density of element is (No. of atoms in bcc, Z = 2).

a) 2.144 g/cm³
b) 7.289 g/cm³
c) 5.188 g/cm³
d) 10.376 g/cm³

Answer : C

Question : What is the coordinatio number of sodium in Na₂O?

a) 6
b) 4
c) 8
d) 2

Answer : B

Question : The compound, found in nature in gas phase but ionic in solid state is

a) PCl₅
b) CCl₄
c) PCl₃
d) POCl₃

Answer : A 

Question : The Ca²⁺ and F^– are located in CaF₂ crystal, respectively at face centred cubic lattice points and in

a) Tetrahedral voids
b) Half of tetrahedral voids
c) Octahedral voids
d) Half of octahedral voids

Answer : B

Question : The coordination number in hcp is

a) 6  
b) 12
c) 18
d) 24

Answer : B

Question : The space lattice of graphite is

a) Cubic    
b) Tetragonal
c) Rhombic
d) Hexagonal

Answer : D

Question : Coordination numbers of Zn²⁺ and S^2– in the crystal structure of wurtzite are

a) 4, 4
b) 6, 6
c) 8, 4
d) 8, 8

Answer : A

Question : Gold has a face centred cubic lattice with an edge length of the unit cube of 407 pm. Assuming the closest packing, the diameter of the gold atom is

a) 576.6 pm
b) 287.8 pm
c) 352.5 pm
d) 704.9 pm

Answer : B

Question : Which is not correct about the Schottky defects?

a) Both cations and anions are missing from their lattice sites without affecting the stoichiometry of the compound
b) Because of presence of holes the lattice energy decreases.
c) The presence of holes causes the density of the crystal to decrease.
d) The defect increases the electrical of the ions into the holes.

Answer : B

Question : The existence of a substance in more than one solid modifications is known as

a) isomorphism
b) Polymorphism
c) Amorphism
d) Allotropy

Answer : B

Question : An element (atomic mass = 100 g / mol) having bcc structure has unit cell edge 400 pm. Then, density of the element is

a) 10.376 g/cm³
b) 5.188 g/cm³
c) 7.289 g/cm³ 
d) 2.144 g/cm³

Answer : B

Question : If AgI crystallises in zinc blende structure with I– ions at lattice points. What fraction of tetrahedral voids is occupied by Ag+ ions?

a) 25%  
b) 50%
c) 100%
d) 75%

Answer : B

Question : Which set of following characteristics for ZnS crystal is correct?

a) Coordination number (4 : 4); ccp; Zn²⁺ ion in the alternate tetrahedral voids
b) Coordination number (6 : 6); hcp; Zn²⁺ ion in all tetrahedral voids.
c) Coordination number (6 : 4); hcp; Zn²⁺ ion in all octahedral voids
d) Coordination number (4 : 4); ccp; Zn²⁺ ion in all tetrahedral voids.

Answer : A

Question : Which one of the following statements about packing in solids is incorrect ?

a) Coordination number in bcc mode of packing is 8.
b) Coordination number in hcp mode of packing is 12.
c) Void space in hcp mode of packing is 32%.
d) Void space is ccp mode of packing is 26%.

Answer : C

Question :   Sodium metal crystallizes in a body centred cubic lattice with a unit cell edge of 4.29Å. The radius of sodium atom is approximately :

a) 5.72Å
b) 0.93Å
c) 1.86Å
d) 3.22Å

Answer : C

Question : Choose the correct option

Assertion :No compound has both Schottky and Frenkel defects.
Reason : Both defects change the density of the solid. 

a) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
b) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) If Assertion is correct but Reason is incorrect.
d) If both the Assertion and Reason are incorrect.

Answer : D

Question : Choose the correct option

Assertion : Stability of a crystal is reflected in the magnitude of its melting.
Reason : The stability of a crystal depends upon the strength of the interparticle attractive force. 

a) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
b) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) If Assertion is correct but Reason is incorrect.
d) If both the Assertion and Reason are incorrect.

Answer : A

Question : Choose the correct option

Assertion : Due to Frenkel defect, there is no effect on the density of the crystalline solid.
Reason : In Frenkel defect, no cation or anion leaves the crystal. 

a) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
b) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) If Assertion is correct but Reason is incorrect.
d) If both the Assertion and Reason are incorrect.

Answer : A

Question : Choose the correct option

Assertion: On heating ferromagnetic or ferrimagnetic substances, they become paramagnetic.
Reason: The electrons change their spin on heating. 

a) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
b) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
c) If Assertion is correct but Reason is incorrect.
d) If both the Assertion and Reason are incorrect. 

Answer : A 

Question : Which of the following is not a characteristic property of solids?

a) Intermolecular distances are short.

b) Intermolecular forces are weak.

c) Constituent particles have fixed positions.

d) Solids oscillate about their mean positions.

Answer : B

Question : Most crystals show good cleavage because their atoms, ions or molecules are

a) weakly bonded together

b) strongly bonded together

c) spherically symmetrical

d) arranged in planes

Answer : D

Question : “Crystalline solids are anisotropic in nature. What is the meaning of anisotropic in the given tement?

a) A regular pattern of arrangement of particles which repeats itself periodically over the entire crystal.

b) Different values of some of physical properties are shown when measured along different directions in the same crystals.

c) An irregular arrangement of particles over the entire crystal.

d) Same values of some of physical properties are shown when measured along different directions in the same crystals.

Answer : B

Question : A crystalline solid

a) changes abruptly from solid to liquid when heated

b) has no definite melting point

c) undergoes deformation of its geometry easily

d) has an irregular 3-dimensional arrangements

Answer : A

Question : Which of the following is not a characteristic of a crystalline solid ?

a) Definite and characteristic heat of fusion.

b) Isotropic nature.

c) A regular periodically repeated pattern of arrangement of constituent particles in the entire crystal.

d) A true solid

Answer : B

Question : Which of the following is not a crystalline solid?

a) KCl

b) CsCl

c) Glas

d) Rhombic S

Answer : C

Question : Which of the following statements about amorphous solids is incorrect ? 

a) They melt over a range of temperature

b) They are anisotropic

c) There is no orderly arrangement of particles

d) They are rigid and incompressible

Answer : B

Question : Which of the following is not a crystalline solid?

a) KCl

b) CsCl

c) Glass

d) Rhombic S

Answer : C

Question : Which of the following is an amorphous solid ?

a) Graphite (C)

b) Quartz glass (SiO₂)

c) Chrome alum

 d) Silicon carbide (SiC)

Answer : B

Question : Which of the following statement is not true about amorphous solids ?

a) On heating they may become crystalline at certain temperature.

b) They may become crystalline on keeping for long time.

c) Amorphous solids can be moulded by heating.

d) They are anisotropic in nature.

Answer : D

Question : The sharp melting point of crystalline solids is due to _____.

a) a regular arrangement of constituent particles observed over a short distance in the crystal lattice.

b) a regular arrangement of constituent particles observed over a long distance in the crystal lattice.

c) same arrangement of constituent particles in different directions.

d) different arrangement of constituent particles in different directions.

Answer : B

Question : Why some glass objects from ancient civilisations are found to become milky in appearance?

a) Glass is a crystalline solid, milky appearance is due to its crystalline nature.

b) Glass is amorphous but on heating it become crystalline at some temperature.

c) Because of reaction of glass with impurities present in the atmosphere.

d) None of these.

Answer : B

Question : Which of the following amorphous solid is used as photovoltaic material for conversion of  unlight into electricity?

a) Quartz glass

b) Quartz

c) Silicon

 d) Both a) and b)

Answer : C

Question : Solid CH₄ is

a) ionic solid

b) covalent solid

c) molecular solid

d) does not exist

Answer : C

Question :  An example of a covalent crystalline solid is:

a) Si

b) Al

c) NaF

d) Ar

Answer : A

Question : Among solids, the highest melting point is exhibited by

a) Covalent solids

b) Ionic solids

c) Pseudo solids

d) Molecular solids

Answer : A

Question : Which of the following exists as covalent crystals in the solid state ?

a) Iodine

b) Silicon

c) Sulphur

d) Phosphorus

Answer : B

Question : The major binding force of diamond, silicon and quartz is

a) electrostatic force

 b) electrical attraction

c) covalent bond force

d) non-covalent bond force

Answer : C

Question : In graphite electrons are :

a) localised on each carbon atom

b) spread out between the sheets

c) localised on every third carbon atom

d) present in antibonding orbital.

Answer : B

Question : Which one of the following forms a molecular solid when solidified?

a) Silicon carbide

b) Calcium fluoride

c) Rock salt

d) Methane

Answer : D

Question : Which of the following is a network solid ?

a) SO₂ (solid)

b) I2

c) Diamond

d) H₂O (Ice)

Answer : C

Question : Which of the following solids is not an electrical conductor?

a) Mg (s)

b) TiO (s)

c) I₂ (s)

d) H₂O (s)

Answer : C

Question : Iodine molecules are held in the crystals lattice by ______.

a) london forces

b) dipole-dipole interactions

c) covalent bonds

d) coulombic forces

Answer : A

Question : Which of the following is not the characteristic of ionic solids?

a) Very low value of electrical conductivity in the molten state.

b) Brittle nature.

c) Very strong forces of interactions.

d) Anisotropic nature.

Answer : A

Question : Graphite is a good conductor of electricity due to the presence of ______.

a) lone pair of electrons

b) free valence electrons

c) cations

d) anions

Answer : B

Question : Graphite cannot be classified as ______.

a) conducting solid

b) network solid

c) covalent solid

d) ionic solid

Answer : D

Question : Which of the following cannot be regarded as molecular solid ?

(i) SiC (Silicon carbide)

(ii) AlN

(iii) Diamond

(iv) I2 

a) (i), (ii) and (iii)
b) (ii) and (iii)
c) (iv)
d) (ii) and (iv)

Answer : A

Question : Crystals can be classified into basic crystal units, equal to

a) 7

 b) 4

c) 14

d) 2

Answer : A

Question : How many three dimensional crystal lattice are possible?

a) 20

b) 7

c) 14

 d) 10

Answer : C

Question : Which of the following is the correct increasing order of packing efficiency for hcp, bcc and simple cubic lattice?

a) hcp < bcc < simple cubic

b) bcc < hcp < simple cubic

c) simple cubic < bcc < hcp

d) simple cubic < hcp < bcc

Answer : C

Question : In face-centred cubic lattice, a unit cell is shared equally by how many unit cells

a) 2

b) 4

c) 6

d) 8

Answer : C

Question : Percentages of free space in cubic close packed structure and in body centered packed structure are respectively

a) 30% and 26%
b) 26% and 32%
c) 32% and 48%
d) 48% and 26%

Answer : B

Question : The empty space in the body centred cubic lattice is

a) 68%
b) 52.4%
c) 47.6%
d) 32%
(e) 74%

Answer : D

Question : Which one of the following statements about packing in solids is incorrect ?

a) Coordination number in bcc mode of packing is 8.

b) Coordination number in hcp mode of packing is 12.

c) Void space in hcp mode of packing is 32%.

d) Void space is ccp mode of packing is 26%.

Answer : C

Question : The number of atoms contained in a fcc unit cell of a monoatomic substance is

a) 1

b) 2

c) 4

d) 6

Answer : C

Question : In face-centred cubic lattice, a unit cell is shared equally by how many unit cells

a) 2

b) 4

c) 6

d) 8

Answer : C

Question : The number of atoms per unit cell of bcc structure is

a) 1

b) 2

c) 4

 d) 6

Answer : B

Question : When molten zinc is converted into solid state, it acquires hcp structure. The number of nearest neighbours of Zn will be

a) 6

b) 12

c) 8

d) 4

Answer : B

Question : Hexagonal close packed arrangement of ions is described as

a) ABC ABA

b) ABC ABC

c) ABABA

d) ABBAB EBD_7207

Answer : C

Question : In which of the following crystals alternate tetrahedral voids are occupied?

a) NaCl

b) ZnS

c) CaF₂

d) Na2O

Answer : B

Question : Which of the following metal(s) show(s) hexagonal close packed structure (hcp) and which show face centredvcubic (fcc) structure? hcp fcc

a) Ag, Zn Mg, Cu

b) Mg, Zn Ag, Cu

c) Cu, Fe Al, Sn

d) Na, Li Zn, Cu

Answer : B

Question : The number of octahedral voids present in a lattice is A . The number of closed packed  articles, the number of tetrahedral voids generated is B the number of closed packed particles

a) A- equal, B- half

b) A- twice, B- equal

c) A- twice , B- half

d) A- equal, B- twice

Answer : A

Question : In the hexagonal close packed structure of a metallic lattice, the number of nearest neighbours of a metallic atom i

a) twelve

b) four

c) eight

d) six

Answer : A

Question : The Ca2+ and F– are located in CaF2 crystal, respectively at face centred cubic lattice points and in

a) tetrahedral voids

b) half of tetrahedral voids

c) octahedral voids

d) half of octahedral voids

Answer : A

Question : If Germanium crystallises in the same way as diamond, thenmwhich of the following statement is not correct?

a) Every atom in the structure is tetrahedrally bonded to 4 atoms.

b) Unit cell consists of 8 Ge atoms and co-ordination number is 4.

c) All the octahedral voids are occupied.

d) All the octahedral voids and 50% tetrahedral voids remain unoccupied.

Answer : C

Question : The arrangement ABC ABC .......... is referred to as

a) Octahedral close packing

b) Hexagonal close packing

c) Tetrahedral close packing

d) Cubic close packing

Answer : D

Question : The total number of tetrahedral voids in the face centred unit cell is ______.

a) 6

b) 8

c) 10

d) 12

Answer : B

Question : What is the coordination number in a square close packed structure in two dimensions ?

a) 2

b) 3

c) 4

d) 6

Answer : C

Question : In the cubic close packing, the unit cell has ______.

a) 4 tetrahedral voids each of which is shared by four adjacent unit cells.

b) 4 tetrahedral voids within the unit cell.

c) 8 tetrahedral voids each of the which is shared by four adjacent unit cells.

d) 8 tetrahedral voids within the unit cells.

Answer : D

Question : In which of the following arrangements octahedral voids are formed ?

(i) hcp (ii) bcc

(iii) simple cubic (iv) fcc

a) (i), (ii)

b) (i), (iv)

c) (iii)

d) (ii), (iv)

Answer : B