CBSE Class 12 Chemistry The Solid State MCQs Set D

Question. The pure crystalline substance on being heated gradually first forms a turbid liquid at constant temperature and still at higher temperature turbidity completely disappears. The behaviour is a characteristic of substance forming
(a) allotropic crystals
(b) liquid crystals
(c) isomeric crystals
(d) isomorphous crystals.

Answer : B

Question. Glass is a
(a) liquid
(b) solid
(c) supercooled liquid
(d) transparent organic polymer.

Answer : C

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. The ability of a substance to assume two or more crystalline structures is called
(a) isomerism
(b) polymorphism
(c) isomorphism
(d) amorphism

Answer : B

Question. Cation and anion combines in a crystal to form following type of compound
(a) ionic
(b) metallic
(c) covalent
(d) dipole-dipole.

Answer : A

Question. For two ionic solids CaO and KI, identify the wrong statement among the following.
(a) CaO has high melting point.
(b) Lattice energy of CaO is much larger than that of KI.
(c) KI has high melting point.
(d) KI is soluble in benzene

Answer : D

Question. For orthorhombic system axial ratios are a ≠ b ≠ c and the axial angles are
(a) α = β = γ ≠ 90º
(b) α = β = γ = 90º
(c) α = γ = 90º, β ≠ 90º
(d) α ≠ β ≠ γ ≠ 90º

Answer : B

Question. The number of carbon atoms per unit cell of diamond unit cell is
(a) 6
(b) 1
(c) 4
(d) 8

Answer : D

Question. In a 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. When Zn converts from melted state to its solid state, it has hcp structure, then find the number of nearest atoms.
(a) 6
(b) 8
(c) 12
(d) 4

Answer : C

Question. The fcc crystal contains how many atoms in each unit cell?
(a) 6
(b) 8
(c) 4
(d) 5.

Answer : C

Question. The number of atoms contained in a fcc unit cell of a monatomic substance is
(a) 1
(b) 2
(c) 4
(d) 6

Answer : C

Question. A compound is formed by cation C and anion A.
The anions form hexagonal close packed (hcp) lattice and the cations occupy 75% of octahedral voids. The formula of the compound is
(a) C₄A₃
(b) C₂A₃
(c) C₃A₂
(d) C₃A₄

Answer : D

Question. In the fluorite structure, the coordination number of Ca2+ ion is
(a) 4
(b) 6
(c) 8
(d) 3

Answer : C

Question. The vacant space in bcc lattice unit cell is
(a) 48%
(b) 23%
(c) 32%
(d) 26%

Answer : C

Question. If a is the length of the side of a cube, the distance between the body-centred atom and one corner atom in the cube will be
(a) 2/√3a
(b) 4/√3a
(c) √3/4a
(d) √3/2a

Answer : D

Question. A metal crystallises with a face-centred cubic lattice.The edge of the unit cell is 408 pm. The diameter of the metal atom is
(a) 288 pm
(b) 408 pm
(c) 144 pm
(d) 204 pm

Answer : A

Question. AB crystallizes in a body-centred cubic lattice with edge length ‘a’ equal to 387 pm. The distance between two oppositely charged ions in the lattice is
(a) 335 pm
(b) 250 pm
(c) 200 pm
(d) 300 pm

Answer : A

Question. Lithium metal crystallises in a body-centred cubic crystal. If the length of the side of the unit cell of lithium is 351 pm, the atomic radius of lithium will be
(a) 151.8 pm
(b) 75.5 pm
(c) 300.5 pm
(d) 240.8 pm

Answer : A

Question. Copper crystallises in a face-centred cubic lattice with a unit cell length of 361 pm. What is the radius of copper atom in pm?
(a) 157
(b) 181
(c) 108
(d) 128

Answer : D

Question. Which of the following statements is not correct?
(a) The number of carbon atoms in a unit cell of diamond is 8.
(b) The number of Bravais lattices in which a crystal can be categorized is 14.
(c) The fraction of the total volume occupied by the atoms in a primitive cell is 0.48.
(d) Molecular solids are generally volatile.

Answer : C

Question. The pyknometric density of sodium chloride crystal is 2.165 × 10³ kg m^–3 while its X-ray density is 2.178 × 103 kg m^–3. The fraction of unoccupied sites in sodium chloride crystal is
(a) 5.96
(b) 5.96 × 10^–2
(c) 5.96 × 10^–1
(d) 5.96 × 10^–3 

Answer : D

Question. The edge length of face-centred unit cubic cells is 508 pm. If the radius of the cation is 110 pm, the radius of the anion is
(a) 144 pm
(b) 398 pm
(c) 288 pm
(d) 618 pm

Answer : A

Question. Iron exhibits bcc structure at room temperature.
Above 900°C, it transforms to fcc structure. The ratio of density of iron at room temperature to that at 900°C (assuming molar mass and atomic radii of iron remains constant with temperature) is
(a) √3/√2
(b) 4√3 /3√2
(c) 3√3 /4√2
(d) 1/2

Answer : C

Question. Lithium has a bcc structure. Its density is 530 kg m^–3 and its atomic mass is 6.94 g mol^–1. Calculate the edge length of a unit cell of lithium metal. (NA = 6.02 × 10²³ mol^–1)
(a) 527 pm
(b) 264 pm
(c) 154 pm
(d) 352 pm

Answer : A

Question. A metal has a fcc lattice. The edge length of the unit cell is 404 pm. The density of the metal is 2.72 g cm^–3. The molar mass of the metal is (NA Avogadro’s constant = 6.02 × 10²³ mol^–1)
(a) 27 g mol^–1
(b) 20 g mol^–1
(c) 40 g mol^–1
(d) 30 g mol^–1

Answer : A

Question. CsBr crystallises in a body-centred cubic lattice.
The unit cell length is 436.6 pm. Given that the atomic mass of Cs = 133 and that of Br = 80 amu and Avogadro number being 6.02 × 10²³ mol^–1, the density of CsBr is
(a) 4.25 g/cm³
(b) 42.5 g/cm³
(c) 0.425 g/cm³
(d) 8.25 g/cm³

Answer : A

Question. An element (atomic mass = 100 g/mol) having bcc structure has unit cell edge 400 pm. The density of element is
(a) 7.289 g/ccm³
(b) 2.144 g/cm³
(c) 10.376 g/cm³
(d) 5.188 g/cm³

Answer : D

Question. Formula of nickel oxide with metal deficiency defect in its crystal is Ni0.98O. The crystal contains Ni2+ and Ni³⁺ ions. The fraction of nickel existing as Ni²⁺ ions in the crystal is
(a) 0.96
(b) 0.04
(c) 0.50
(d) 0.3

Answer : A

Question. The correct statement regarding defects in crystalline solids is
(a) Frenkel defects decrease the density of crystalline solids
(b) Frenkel defect is a dislocation defect
(c) Frenkel defect is found in halides of alkaline metals
(d) Schottky defects have no effect on the density of crystalline solids.

Answer : B

Question. The appearance of colour in solid alkali metal halides is generally due to
(a) interstitial positions
(b) F-centres
(c) Schottky defect
(d) Frenkel defect.

Answer : B

Question. In calcium fluoride, having the fluorite structure, the coordination numbers for calcium ion (Ca2+) and fluoride ion (F–) are
(a) 4 and 2
(b) 6 and 6
(c) 8 and 4
(d) 4 and 8

Answer : C

Question. The ionic radii of A+ and B– ions are 0.98 × 10_–10 m and 1.81 × 10_–10 m. The coordination number of each ion in AB is
(a) 8
(b) 2
(c) 6
(d) 4

Answer : C

Question. The number of octahedral void(s) per atom present in a cubic close-packed structure is
(a) 1
(b) 3
(c) 2
(d) 4

Answer : A

Question. Structure of a mixed oxide is cubic close packed (ccp). The cubic unit cell of mixed oxide is composed of oxide ions. One fourth of the tetrahedral voids are occupied by divalent metal A and the octahedral voids are occupied by a monovalent metal B. The formula of the oxide is
(a) ABO₂
(b) A₂BO₂
(c) A₂B₃O₄
(d) AB₂O₂

Answer : D

Question. A solid compound XY has NaCl structure. If the radius of the cation is 100 pm, the radius of the anion (Y–) will be
(a) 275.1 pm
(b) 322.5 pm
(c) 241.5 pm
(d) 165.7 pm

Answer : C

Question. A compound formed by elements X and Y crystallises in a cubic structure in which the X atoms are at the corners of a cube and the Y atoms are at the facecentres.
The formula of the compound is
(a) XY₃
(b) X₃Y
(c) XY
(d) XY₂

Answer : A

Question. In cube of any crystal A-atom placed at every corners and B-atom placed at every centre of face. The formula of compound is
(a) AB
(b) AB₃
(c) A₂B₂
(d) A₂B₃

Answer : B

Question. In crystals of which one of the following ionic compounds would you expect maximum distance between centres of cations and anions?
(a) CsI
(b) CsF
(c) LiF
(d) LiI

Answer : A

Question. The second order Bragg diffraction of X-rays with λ = 1.00 Å from a set of parallel planes in a metal occurs at an angle 60°. The distance between the scattering planes in the crystal is
(a) 2.00 Å
(b) 1.00 Å
(c) 0.575 Å
(d) 1.15 Å

Answer : D

Question. The intermetallic compound LiAg crystallizes in cubic lattice in which both lithium and silver have coordination number of eight. The crystal class is
(a) face-centred cube
(b) simple cube
(c) body-centred cube
(d) none of these.

Answer : C

Question. Schottky defect in crystals is observed when
(a) density of the crystal is increased
(b) unequal number of cations and anions are missing from the lattice
(c) an ion leaves its normal site and occupies an interstitial site
(d) equal number of cations and anions are missing from the lattice

Answer : D