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I. Multiple Choice Questions (Type-]), , 1., , Which of the following conditions favours the existence of a substance in the, solid state?, , fi) High temperature, , ii}, Low temperature, , (iii) High thermal energy, , (1v) Weak cohestve forces, , Which of the following is not a characteristic of a crystalline solid?, , (i) Definite and characteristic heat of fusion,, , (i) Isotropic nature., , (iii) A regular periodically repeated pattern of arrangement of constituent, particles in the entire crystal., , (iv) A true solid, , Which of the following is an amorphous solid?, , (i) Graphite (C), , (i) Quartz glass (SiO,), (iii) Chrome alum, (iv) Silicon carbide (SiC), , Which of the following arrangements shows schematic alignment of magnetic, moments of antiferromagnetic substances?, , © OOOOOO, eo OQOOOOO
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7., , 10., , » OOOOOO, m OOOOOO, , Which of the following is true about the value of refractive index of quartz glass?, (i) Same in all directions, (ii) ‘Different in different directions, (iii) Cannot be measured, (iv) Alway's zero, Which of the following statement is not true about amorphous solids?, fi) On heating they may become crystalline at certain temperature., (ii) They may become crystalline on keeping for long time., (iii) Amorphous solids can be moulded by heating., (tv) They are anisotropic in nature., , The sharp melting point of crystalline solids is due to, , (i) a regular arrangement of constituent particles observed over a short, distance in the crystal lattice., , (i) a regular arrangement of constituent particles observed over a long, distance in the crystal lattice., , (iii) same arrangement of constituent particles in different directions., (iv) different arrangement of constituent particles in different directions,, , lodine molecules are held in the crystals lattice by, {) london forces, (ii) dipole-dipole interactions, (iii) covalent bonds, () ~—s coulombic forces,, , Which of the following is a network solid?, W SO, (Solid), fi) L, (ii) |= Diamond, (iv) -H,O llce), Which of the following solids is not an electrical conductor?, (A) Mg {s) (B) TiO (s) (Cc) 1, {s) {D) H,0 (s), , ) (A) only, (i) (B) Only, (iii) (C) and (D), (iv) (B), (C) and (D), , Exemplar Problems, Chemistry gales
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11,, , 12., , 13., , 14,, , 15., , 16., , 17., , Which of the following is not the characteristic of ionic solids?, (i) Very low value of electrical conductivity in the molten state., (ii) Brittle nature., {iti} Very strong forces of interactions., (iv) Anisotropic nature., , Graphite is a good conductor of electricity due to the presence of, (i) lone pair of electrons, (i) free valence electrons, {tti) cations, (iv) anions, Which of the following oxides behaves as conductor or insulator depending, upon temperature?, TIO, ii], SiO,, (ii) TiO,, (vw) MgO, , Which of the following oxides shows electrical properties like metals?, f) S10,, (i) ~Mgo, (iii) SO,{s), liv) Cro,, , ‘The lattice site in a pure crystal cannot be occupied by, (i) molecule, fii) ion, , {iii) electron, , (iv) atom, , Graphite cannot be classified as, (i) conducting solid, (ii) network solid, (iii) covalent solid, {iv] ionic solid, , Cations are present in the interstitial sites in, f) Frenkel defect, (ii) Schottky defect, {iii} Vacancy defect, (iv) Metal deficiency defect, , =a Solid Sta, , ZO
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18., , 19., , 21., , Schottky defect is observed in crystals when ., {) some cations move from their lattice site to interstitial sites., (ii) equal number of cations and anions are missing from the lattice., (iii) some lattice sites are occupied by electrons., (iv) some impurity is present in the lattice., , Which of the following is true about the charge acquired by p-type, semiconductors’?, , {i) positive, (ii) = neutral, (iii) negative, (iv) depends on concentration of p impurity, , To get a n-type semiconductor from silicon, tt should be doped with a, substance with valence., , 2, (i) 1, (ii) 3, iy) 5, ‘The total number of tetrahedral voids in the face centred unit cell is, f) 6, (i) 8, Gi) «10, () 12, , Which of the following point defects are shown by AgBr(s) crystals?, , {A) Schottky defect (RB) Frenkel defect, (C) Metal excess defect (D) Metal deficiency defect, , () (A) and (B), (i) (C) and (b), (ii) = (A) and (C), (iv) (B) and (D), In which pair most efficient packing is present?, {i) hepand bee, (i) hepand ecp, (ii) beeand cep, fv) bee and simple cubic cell, , The percentage of empty space in a body centred cubic arrangement is, , Exemplar Problems, Chemistry gues
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(ii), (ii), (tv), , 68, 32, 26, , Which of the following statement is mot true about the hexagonal close, packing?, , (), (ii), (iii), , (iv), , The coordination number is 12., It has 74% packing efficiency., , Tetrahedral voids of the second layer are covered by the spheres of the, third layer., , In this arrangement spheres of the fourth layer are exactly aligned with, those of the first layer., , In which of the following structures coordination number for cations and, anions in the packed structure will be same?, , i), (i), (iii), , (tv), , Cl ion form fcc lattice and Na‘ ions occupy all octahedral voids of the, unit cell., , Ca* tons form fec lattice and F tons oecupy all the eight tetrahedral, voids of the unit cell,, , 0” ions form fcc lattice and Na* ions occupy all the eight tetrahedral, voids of the unit cell., , S* tons form fee lattice and Zn” tons go into alternate tetrahedral voids, of the unit cell., , What is the coordination number in a square close packed structure in two, dimensions?, , (i), (i), (tit), (iv), , 2, , 3, 4, 6, , Which kind of defects are introduced by doping?, , (i), (ii), (iii), (iv), , Dislocation defect, Schottky defect, Frenkel defects, Electronic defects, , Silicon doped with electron-rich impurity forms, , (i), (ii), (iii), tiv), , p-type semiconductor, n-type semiconductor, intrinsic semiconductor, insulator, , ni Solid Sta