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S Multiple Choice Questions (MCQs), , 1. Which of the following does not, , radius of the atom correctly? nepreeent, , (i) Simple cubic cell : Radius of the atom =2, , (ii) Face centred cubic cell : Radius =—“, wW3, , (iii) Body centred cubie cell : Radius = Ya, , (a) @ (b) (ii), , (c) Gi) (d) (i) and (ii), , 2. Solid x is avery hard solid which is electrical, insulator in solid as well as in molten state and, has extremely high melting point. What type of, solid is it?, , (a) Ionic solid (b) Covalent solid, , (c) Metallic solid (d) Molecular solid, , 3. A compound is formed by two elements Y, , and Z. The element Z forms ccp and atoms Y, , occupy 1/8rd of tetrahedral voids. The formula, , of the compound is, , (a) YoZ3 (b) ¥Z, , (c) YZ3 (d) YZ, , 4. Ionic solids conduct electricity in molten, , state but not in solid state because, , (a) in molten state free ions are furnished which, are not free to move in solid state, , (b) in solid state ionic solids are hard and brittle, and become soft in molten state, , (c) all solids conduct electricity in molten state, , (d) in solid state ions are converted to atoms, which are insulators., , 5. Monoclinic sulphur is an example of, , monoclinic crystal system. What are the, , characteristics of the crystal system?, , (a) a#b #0,a=Bp=y=90°, , (b) azb4c,a#BPFY#90°, , (:) a=b 4c, a=Bp=7= 90°, , (a) a#b 4c, a=7= 90%, B# 90°, , 6. Match the column I with column II and, , mark the appropriate choice., , , , Column I Column II, (Radius ratio) (Coordination, number), (A) 0.155 - 0.225 (i) 4, (B) 0.225 - 0.414 (ii) 8, (C) 0.414 - 0.732 Gii) 3, (D) 0.782 - 1.0 (iv) 6, , (a), (b), , (A) > @, (B) > Gi), (C) > iv), (D) — Git), (A) > (ii), (B) > (iv), (C) > (i), (D) > (iii), (c) (A) > (iv), (B) > Gii), (C) > @, (D) > Gi), (d) (A) > (iii), (B) > (i), (C) > (iv), (D) > Gi), 7. In face centred cubic unit cell, edge length, is, , (a) 5 (b) zr, (c) ar (a) 4,, , 8. How many lithium atoms are present in, a unit cell with edge length 3.5 A and density, 0.53 g em? (Atomic mass of Li = 6.94), , (a) 2 (b) 1, , (c) 4 (d) 6, , 9. Silver halides generally show, , (a) Schottky defect, , (b) Frenkel defect, , (c) both Frenkel and Schottky defects, , (d) cation excess defect., , 40. Which of the following statements is not, , correct regarding covalent crystals diamond and, , graphite?, , (a) In diamond, each carbon atom is covalently, bonded to four other carbon atoms., , (b) In graphite, each carbon atom is covalently, bonded to three other carbon atoms in the, same plane., , (c) The C — C bond length in graphite is, intermediate between single and double, bond., , (d) Diamond is a layered structure, the two, layers joined by van der Waals’ forces.

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6, , 11. Which of the following structures is not, correctly matched?, , (a) NaCltype - Cl ions in ccp structure., Na’ ions in half octahedral, holes., , (b) ZnS type - S* ions in cep structure., Zn** ions in alternate, tetrahedral voids., , (c) CaF, type - Ca?* ions in cep structure., F” ions in all tetrahedral, voids., , (d) Na,O type - O* ions in cep structure., Na* ions in all tetrahedral, holes., , 12. Which of the following statements is not, , true about the voids?, , (a) Octahedral void is formed at the centre of six, spheres which lie at the apices of a regular, octahedron., , (b) There is one octahedral site for each sphere., , (c) There are two tetrahedral sites for each, sphere., , (d) Octahedral voids are formed when the, triangular voids in second layer exactly, overlap with similar voids in the first layer., , 13. Which among the following will show, , , , anisotropy?, (a) Glass (b) NaBr, (c) Plastic (d) Rubber, , 14. In the following figure the blank X in known, as and why?, , ©®O@O®, , @OO®, O@O®, OO®, OO®, , © © O®, , (a) Electron trap, because an electron is present, here., , , , a, , MG CBSE Board Term-I Chemistry Class-12, , (b) Metal deficient centre, since ni, is present here,, , (c) F-centre, since it im, crystal,, , (d) P-centre, since it is res, charge on the crystal., , eBative charge, Parts colour to tha, , ponsible for positive, , 15. What type of crystal defect is shown in th,, figure given below? ., Na* CI” Na* CI” Nat, cr) cr nat cr, Nat Cl Na+] Nat, cr ntQ cog, Nat CI” Nat CI” Nat, (a) Frenkel defect, (b) Schottky defect, (c) Interstitial defect, (d) Cation excess defect, 16. Study the figure of a solid given below, , depicting the arrangement of particles. Which, is the most appropriate term used for the figure?, , , , (a) Isotropy, (b) Anisotropy, (c) Irregular shape, (d) Amorphous nature, 17. Examples of few solids are given below. Find, out the example which is not correctly matched., (a) Tonic solids - NaCl, ZnS, (b) Covalent solids - He, I,, (c) Molecular solids - H)0;,), Urea, (d) Metallic solids - Cu, Sn, 18. Complete the following table :, Point defects, , (4) ” ©, =, Schottky Frenkel (D) Metal, defect defect deficiency, defect

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The Solid State, , (A) (B) (c) (D), (a) Impurity Stoichio- Non- Ani, defects metric stoichio- ecase, defects metric defects, defects, (b) Stoichio- Non- Impurity Metal, metric stoichio- defects excess, defects metric defects, defects, (c) Non- Stoichio- Impurity Cation, Stoichio- metric defects vacancy, metric defects, defects, (d) Impurity Stoichio- Metal Non defects metric excess stoichiodefects defects metric, defects, , 19. The unit cell of aluminium is a cube with an, edge length of 405 pm. The density of aluminium, is 2.70 g cm”. What is the structure of unit cell, of aluminium?, , (a) Body-centred cubic cell, , (b) Face-centred cubic cell, , (c) End-centred cubic cell, , (d) Simple cubic cell, , 20. If three elements X, Y and Z crystallise ina, cep lattice with X atoms at the corners, Y atoms, at the cube centre and Z atoms at the edges, the, formula of the compound will be, , (a) XYZ (b) XYZ,, , (c) XYZ, (d) Xo¥_Z, , 21. NaCl type crystal (with coordination no., 6 : 6) can be converted into CsCl type crystal, (with coordination no. 8 : 8) by applying, , (a) high temperature, , (b) high pressure, , (c) high temperature and high pressure, , (d) low temperature and low pressure., , 22. The density of a metal which crystallises in, bcc lattice with unit cell edge length 300 pm and, molar mass 50 g mol” will be, , (a) 10gcm™> (b) 14.2 gem, , (c) 6.15 gem (a) 9.32 gem, , 23. In the given crystal structure what should, be the cation X which replaces Na’ to create a, cation vacancy?, , (a) Sr, (c) Li*, 24. A crystalline structure has radius ratio, (rg. /rg-) in the range of 0.225 - 0.414. The, coordination number and arrangement of anions, around the cations is, (a) 8, plane triangular (b) 6, octahedral, (c) 4, tetrahedral (d) 8, cubic., 25. Which of the following primitive cells show, the given parameters?, , a#b#c, a=B=y=90°, (a) Cubic (b) Tetragonal, (c) Orthorhombic (d) Hexagonal, 26. If the distance between Na* and Clin NaCl, crystal is 265 pm, the edge length of the unit cell, will be, , (a) 265 pm (b) 795 pm, , (c) 132.5 pm (d) 530 pm, , 27. Fill in the blanks by choosing the correct, option., , Metals often occur in _x_ condition. Individual, crystals are randomly oriented so a metallic, sample may appear to be _y__ even though a, single crystal is _z, , x y z, (a) crystalline isotropic anisotropic, (b) polycrystalline isotropic anisotropic, (c) anisotropic isotropic crystalline, (d) crystalline anisotropic isotropic, , 28. In CaF, type (fluorite structure) Ca** ions, form _(A)_ structure and F- ions are present in, all B)_voids. The coordination number of ‘Ca’, is (©)_and Fis)., , (A), (B), (C) and (D) respectively are, , (A) (B) (©) (D), (a) ecp octahedral 8 4, (b) bee tetrahedral 4 8, (c) cep tetrahedral 8 4, (d) cep octahedral 4 8

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8, 29. Which is the defect represented by the given, , figure? age Ooo, QUO GOO, Bee, OOO OOO, , (a) Schottky defect (b) Frenkel defect, , (c) Vacancy defect (d) Interstitial defect, 30. Coordination numbers of Cs* and CI in, CsCl crystal are, , (a) 8,8 (b) 4,4, , (c) 6,6 (d) 8,4, , 31. Match the column I with column II and, mark the appropriate choice., , Column I Column IT, (Structure) (Packing, efficiency), (A) Simple cubic structure G) 68%, (B) Face centred cubic structure (ii) 74%, (C) Body centred cubic structure (iii) 52%, , (a) (A) > Gii), (B) > (ii), (C) > Gi), , (b) (A) > (i), (B) > (ii), (C) > iii), , (c) (A) > Gi), (B) > @, (C) > Gi), , (d) (A) > Gi), (B) > (i), (C) > Gi), , 32. Which of the following statements is not, , true?, , (a) Silicon carbide is a covalent crystal., , (b) Molecular crystals are soft in nature., , (c) In calcium fluoride structure, coordination, number of Ca”* is 4,, , (d) Increase in radius ratio results in increase, in coordination number., , 33. Match the column I having type of lattice, , point and its contribution to one unit cell in, , column II and mark the appropriate choice., Column I Column II, (Lattice point) (Contribution to, , one unit cell), , (A) Corner @ 1, , (B) Edge Gi) 1/8, , (C) Face centre (iii) 1/4, , (D) Body centre (iv) 1/2, , NS, , MG CBSE Board Term-| Chemistry Class.1,, , (a) (A) > (ii), (B) (i), (C, (b) (A) > (ii), (B) (ii), (, (c) (A) > (i), (B) 5 (ii), (C, (d) (A) > (iii),, , ) > Gi), D) 5 (iy), C) + (iv), D)s (i), ) — (iv), (D) 4 Gi), (B) > (iv), (C) > ), (D) 5 (ii), 34. In the table given below, di, angles of various crystals are gi, the table by filling the blanks,, , Type of crystal Dimensions, , mensions and, ven. Complete, , Angles, , 1. Cubic a=b=c a=Bay, =D, , 2. Tetragonal q H=B=y= 990, , 3. Orthorhombic a # b ¥¢ r, , 4, Hexagonal —o_. O=B = 99°, Yt., , Pp q r 8, , (a) 90° a=bec a=B=y=90°, , a=bae 129°, (b) 120° a=b=c a=90,B=7=120° asbee 90°, (c) 90° a¥b=c a=B=y=120° atbec 99°, (d) 120° azb#c azpey490° atb=e 129°, , 35. In Zinc blende structure,, , (a) zinc ions occupy half of the tetrahedral sites,, , (b) each Zn® ion is surrounded by six sulphide, lons, , (c) each S* ion is surrounded by six Zn* ions, , (d) all of these., , 36. Match the column A with column B and, select the correct option., , Column A Column B, Tonic solid I. NaCl, Metallic solid Il. Fe, , Covalent solid III. C(graphite), Molecular solid IV. Dry ice, , (a) A-II, B-I, C-IV, D-III, , (b) A-I, B-II, C-II, D-IV, , (c) A-III, B-II, C-I, D-IV, , (d) A-H, B-IV, C-I, D-III, , 37. Which of the following statements is not, correct about molecular crystals?, , Sap, , (a) They are generally soft and easily, compressible.

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The Solid State, , (b) They are good conductors of electricity as, the electrons are delocalised in bonds., , (c) They have low melting and boiling points., , (d) They consist of polar or non-polar molecules., , 38. Which of the following defects is represented, in the given figure?, , e008, (a) Impurity defect, (b) Frenkel defect, (c) Schottky defect, (d) Metal excess defect, , 39. Ametal crystallises into a lattice containing, asequence of layers as AB AB AB ............ . What, percentage of voids are left in the lattice?, , (a) 72% (b) 48%, , (c) 26% (d) 32%, , 40. If the radius of an octahedral void is r and, radius of atoms in close packing is R, the relation, between r and R is, , , , (a) r=0.414R (b) R =0.414r, (c) r=2R (d) r= 2R, , 41. A cubic solid is made up of two elements P, and Q. Atoms of P are present at the corners, of the cube and atoms of Q are present at body, centre. What is the formula of the compound and, what are coordination numbers of P and Q?, , (a) PQ:, 6:6 (b) PQ, 6:6, , (c) P,Q, 6:8 (d) PQ, 8:8, , 42. Total volume of atoms present in a fcc unit, cell of a metal with radius r is, , 16, (a) 2a ) 3”, 20, © 3” (a) nF, , 43. Copper crystallises in fcc with a unit cell, length of 361 pm. What is the radius of copper, atom?, , (a) 157 pm, (c) 127 pm, , (b) 181 pm, (d) 108 pm, , 9, , 44. The fraction of the total volume occupied by, the atoms present in a simple cube is, , © E, (a) Z (b) é, , t n, © Ma @ WF, , 45. Volume occupied by single CsCl ion pair ina, crystal is 7.014 x 10-9 cm’. The smallest Cs — Cs, internuclear distance is equal to length of the, side of the cube corresponding to volume of one, CsClion pair. The smallest Cs to Cs internuclear, distance is nearly, , (a) 444A (b) 4.34, , (@) 4A (a) 4.5 A., , 46. What type of stoichiometric defect is shown, by ZnS?, , (a) Schottky defect, , (b) Frenkel defect, , (c) Both Frenkel and Schottky defects, (d) Non-stoichiometric defect, , 47. Formula of nickel oxide with metal deficiency, defect in its crystal is Nig 9g0. The crystal, contains Ni?* and Ni** ions. The fraction of, nickel existing as Ni?* ions in the crystal is, , (a) 0.94 (b) 0.04, , (c) 0.50 (d) 0.3, , 48. The edge length of sodium chloride unit cell, is 564 pm. If the size of Cl ion is 181 pm. The, size of Na* ion will be, , (a) 101 pm (b) 181 pm, , (c) 410 pm (d) 202 pm, , 49. The unit cell shown in the figure belongs to, , , , (a) NaCl type, (c) CsCl type, , (b) ZnS type, , (d) CaF, type., , 50. The edge length of unit cells in terms of, radius of spheres for fcc is_X_, for bec _Y and, for sccis_Z_.