1. The coordination number of atoms in a cubic closed-packed is ________.
(A) 2
(B) 8
(C) 12
(D) 6

Ans: (C) 12

2.The coordination number of atoms in a body-centred cubic structure is ________.
(A) 4
(B) 8
(C) 6
(D) 12

Ans: (B) 8

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3.The type defect observed in ionic crystals which large difference in the size of ions is:
(A) Interstitial defect
(B) Frenkel defect
(C) Schottky Defect
(D) Stoichiometric Defect

Ans: (B) Frenkel defect

4.A mixed oxide has ccp arrangement in which the cations 'X' occupy 1/3rd of octahedral voids and the cations 'Y' occupy 1/3rd of tetrahedral voids.The formula of oxide is:
(A) X ₂Y ₃O ₂
(B) XY ₃O
(C) X ₂YO ₃
(D) XY ₂O ₃

Ans: (D) XY ₂O ₃

5.An element with molar mass 64 gmol ^-1 and density 6.6 g cm ^-3 forms a cubic unit cell.The edge length of unit cell is 4 x 10 ^-8cm.The type of cubic unit cell formed is ?
(A) fcc
(B) ccp
(C) bcc
(D) hcp

Ans: (A) fcc

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6.A solid is made up of 2 elements P and Q. Atoms Q are in ccp arrangement,while P atoms occupy all the tetrahedral sites.The formula of the compound is:
(A) PQ ₂
(B) P ₆Q ₄
(C) P ₂Q
(D) PQ

Ans: (C) P ₂Q

7.A compound is formed by two elements X and Y. Atoms of the element Y (as anions) make ccp and those of the element X (as cations) occupy all the octahedral voids. The formula of the compound is :
(A) X ₂Y
(B) X ₄Y
(C) XY
(D) XY ₂

Ans: (C) XY

8.Atoms of element B form hcp lattice and those of the element A occupy 2/3rd of tetrahedral voids. The formula of the compound formed by the elements A and B is:
(A)A ₄B ₃
(B)A ₂B
(C)A ₃B ₄
(D)AB

Ans: (A) A ₄B ₃

9.An element with molar mass 2.7 x 10 ^-2 kg mol ^-1 forms a cubic unit cell with edge length 405 pm. If its density is 2.7 x 10 ³ kg m ^-3,the nature of cubic unit cell is :
(A) hcp
(B) ccp
(C) bcc
(D) fcc

Ans: (D) fcc

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10.Name the defects noticed when a solid is heated.
(A) Frenkel Defect (B) Interstitial Defect (C) Schottky Defect (D) Vacancy Defect

Ans: (D) Vacancy Defect

11.The packing efficiency of a metal crystal for a simple cubic lattice is :
(A) 65%
(B) 52.4%
(C) 60%
(D) 54.5%

Ans : (B) 52.4%

12.The point defect noticed when AgCl is doped with CdCl2 is :
(A) Frenkel Defect
(B) Vacancy Defect
(C) Metal excess Defect
(D) Impurity Defect

Ans: (D) Impurity Defect

13.An element possess cubic close packing structure.Calculate the radius (r) of the atom in the unit cell.(The edge length of unit cell is a=252 nm)
(A) 89.36 nm
(B) 126 nm
(C) 152 nm
(D) 109.1 nm

Ans: (A) 89.36 nm

14.In a crystal of compound having molecular formula X ₂Y ₃, Y atoms are arranged as CCP, then what fraction of tetrahedral voids will be covered by X atoms?
(A) 1/3
(B) 1/4
(C) 2/3
(D) 3/4

Ans: (C) 2/3

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15.In which of the following defect some of the cations are arranged in the interstitial site?
(A) Schottky defect
(B) Frenkel defect
(C) Metal excess defect
(D) Interstitial defect

Ans: (B) Frenkel defect

16.Chromium metal crystallises in a body centred cubic lattice. The length of the unit cell edge is found to be 287 pm. The atomic radius of chromium:
(A) 120.24 pm
(B) 100 pm
(C) 134.10 pm
(D) 124.12 pm

Ans: (D) 124.12 pm

17.In a fcc arrangement of P and Q atoms, P atoms are at the corners and Q atoms at face centres of the unit cell, what is the formula of the compound?
(A) PQ
(B) P ₃Q
(C) PQ ₃
(D) P ₂Q ₂

Ans: (C) PQ ₃

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18.A compound forms hexagonal close packed structure. What is the total number of voids in 0.5 mole of it?
(A) 3.01 x 10 ²³
(B) 9.03 x 10 ²³
(C) 6.02 x 10 ²³
(D) 8.33 x 10 ²³

Ans: (B) 9.03 x 10 ²³

19.The defect produced when NaCl is doped with SrCl ² is:
(A) Thermodynamic Defect
(B) Interstitial Defect
(C) Frenkel Defect
(D) Vacancy Defect (Metal deficiency type)

Ans: (D) Vacancy Defect (Metal deficiency type)

20. Ionic solids conduct electricity in molten state but NOT in solid state because :
(A) ionic solids absorb water in molten state which conducts electricity
(B) electrons are evenly spread throughout the crystal in the solid state
(C) the covalent bonds holding the ionic solid together are broken in molten state
(D) ions in the solid state are not free to move, but ions become free to move in the molten state

Ans: (D) ions in the solid state are not free to move, but ions become free to move in the molten state

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21. For a body-centered cubic structure with unit cell edge length of a , the radius of the sphere of each atom is :
(A) √3/4 a
(B) a/2√2
(C) a/2
(D) a/4

Ans: (A) √3/4 a

22. In a sample of naturally occuring iron oxide, every 30 out of 200 Fe²⁺ ions are missing.The loss of positive charge is made up by adding required number of Fe³⁺ ions so as to restore electrical neutrality.The net formula for this sample is:
(A) Fe_0.7O
(B) Fe_0.8O
(C) Fe_0.9O
(D) Fe_0.95O

Ans: (D) Fe_0.95O

23. When silicon is doped with aluminuim
(A) excess of aluminuim ions will form that mobilize to conduct electricity
(B) the mixture will become an insulator
(C) excess of holes will form
(D) conductivity will increase due to excess delocalized electrons

Ans: (C) excess of holes will form

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24.The material with atoms A occupying face centered cubic lattice, B occupying one-third of the tetrahedral voids and C occupying half of the octahedral voids has the formula:
(A) A₃BC₃
(B) A₆B₄C₃
(C) A₆B₂C₃
(D) AB₂C

Ans: (B) A₆B₄C₃

25. Which of the following is a network crystalline solid?
(A) I₂
(B) NaCl
(C) AIN
(D) Ice

Ans: (C) AIN

26.The number of atoms in 2.4g of body centered cubic crystal with edge length 200pm is (density = 10g cm^-3, NA = 6 x 10²³ atoms/mol)
(A) 6 x 10²²
(B) 6 x 10²³
(C) 6 x 10²⁰
(D) 6 x 10¹⁹

Ans: (A) 6 x 10²²

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27.In F.C.C the unit cell is shared equally by how many unit cells?
(A) 10
(B) 8
(C) 6
(D) 2

Ans: (C) 6

28.The correct statement regarding defect in solids is:
(A) Frenkel defect is usually favoured by a very small difference in the sizes of cations and anions
(B) Frenkel defect is a dislocation defect
(C) Trapping of protons in the lattice leads to the formation of F-centers
(D) Schottky defect has no effect on the physical properties of solids

Ans: B) Frenkel defect is a dislocation defect.

29.In a face centred cubic arrangement of A and B atoms in which 'A' atoms are at the corners of the unit cell and 'B' atoms are at the face centers. One of the 'A' atom is missing from one corner in the unit cell. The simplest formula of compound is
(A) A₇B₂₄
(B) A₇B₈
(C) AB₃
(D) A₇B₃

Ans: (A) A₇B₂₄

30.Which of the following is NOT a characteristic of a covalent compound?
(A) Low melting point
(B) No definite geometry
(C) Insoluble in polar solvent
(D) Small difference in electronegativity between the combining atoms

Ans: B) No definite geometry

31.Which one of the following is a covalent crystal?
(A) Rock salt
(B) Ice
(C) Quartz
(D) Dry Ice

Ans: C) Quartz

32.A compound is formed by elements A and B. This crystallises in the cubic structure where the A atoms are at the corners of the cube and B atoms are at the body centres. The simplest formula of the compound is :
(A) AB
(B) A₆B
(C) A₈B₄
(D) AB₆

Ans: A) AB