M0.98 O. Metal M, present as M and M+2 in its oxide. Fraction of the metal which exists as M +3 would be a. 7.01% b. 4.08% c. 6.05 % d. 5. 08% Ans. b (32)
a. Non- stoichiometric defects b. Shottky defects c. Frenkel defects d. all the above Ans. b (28)
10-4 mol % of SrCl2 the concentration of cation vacancies will be a. 6.02 x 1015 mol -1 b. 6.02 x 1016 mol -1 c. 6.02 x 1017 mol -1 d. 6.02 x 1014 mol -1 Ans. c (7)
a. Selenium b. Boron c. Germanium d. Arsenic Ans. b Explanation : Boron can easily form positive ion. When silicon is doped with boron, it creates a positive hole and the substance are called p type semicondutor. (5)
a. Ferroelectric effect b. Pyrelectric effect c. Antiferroelectric effect d. piezoelectric effect Ans. b Explanation : pyroelectircity : It is the electricity produced when some polar crystals are heated (6)
a. Positive b. Neutral c. Negative d. Depends on concentration of p impurity Ans. b (4)
a. Frenkel defect b. Sohottky defect c. Intersitital defects d. F- centre Ans. d Explanation : When electorns are trapped in anion vacancies these are called F centres (8)
a. F centre b. Frenkel c. Sohottky d. Interstital Ans. c Explanation : During the schottkky defects same number of cations and anions are missing from their lattice site so density is decreased. (9)
a. Schotky defect b. Frenkel defect c. Stoichiometric defect d. F- centres Ans. d Explanation : F- centres are the sites where anions are missing and instead electrons are present they are responsible for colour. (6)
a. Frenkel defect b. Interstitial positions c. F- centres d. Schottky defects Ans. c (6)
a. Interstitial defect b. Valency defect c. Frenkel defect d. Schottky defect Ans. c (8)
a. Nucleus defects b. Non-crystal defects c. Crystal defects d. None of these Ans. c Explanation : Both are stoichiometric crystalline defects (6)
a. Increases b. decreases c. Does not change d. Changes Ans. c Explanation : Since no ions are missing from the crystal as s whole, there is no effect on density (28)
a. Schottky defects have no effect on the density of crystalline solids b. Frenkel defects decrease the density of crystalline solids c. Frenkel defect is a dislocation defect d. Frenkel defect is found in halides of alkaline metals. Ans. c …
a. Electron are held in the voids of crystals b. F- centre produces colour to the crystal c. Conductivity of the crystal increases due to F- centre d. All of the above Ans.d Explanation : All the given statements are …
a. A 2 BO4 b. A 2 B 2 O c. A B2 O4 d. A 4 B2 O Ans. c (36)
A2 B 2 has the hcp lattice. Which atom forms the hcp lattice and what fraction of tetrahedral voids is occupied by the other atoms: a. hcp lattice – A, 2/3 Tetrahedral voids B b. hcp lattice – B, 1/3 Tetrahedral …
O2- ions where half the octahedral voids are occupied by Al 3+ and one eight of the tetrahedeal voids are occupied by Mn2+ . The chemical formula of the mineral is. a. Mn3 Al 2 O 6 b. Mn Al 2 O 4 c. …
a. 2 b. 4 c. 6 d. 8 Ans. d (11)
a. NaCl structure b. Fe2 O3 structure c. CaF2 structure d. Na2 O structure Ans. a (26)
a. 6, 6 b. 8, 4 c. 4, 4 d. 4, 8 Ans. b (6)
a. Coordination number ( 4 : 4); ccp; Zn++ ion in the alternate tetrahedral voids b. Coordination number ( 6 : 6); hcp; Zn++ ion in the alternate tetrahedral voids c. Coordination number ( 6 : 4); hcp; Zn++ ion …
Na + and Cl – ions is sodium chloride crystal is X pm, the length of the edge of the unit cell is a. 4X pm b.X/4 pm c. X/2 pm d. 2X pm Ans. d (7)
a. Increase b. Decrease c. Remain the same d. Either (b) or (c) Ans. a (11)
a. 241. 5 pm b. 165. 7 pm c. 275.1 pm d. 322. 5 pm Ans. a (10)
Na+ and Cl– ions are 95 pm and 181 pm respectively. The edge legth of NaCl unit cell is a. 276 pm b. 138 pm c. 552 pm d. 415 pm Ans. c (14)
a. Twelve b. Four c. Eight d. Six Ans. a Explanation : Coordination number in hcp and ccp arrangement is 12 while in bcc arrangement is 8. (7)
a. NaCl type b. CsCl type c. ZnS type d. None of these Ans. b Explanation : Radius ration range 0.732- 0.99 signifies coordination number 8. In CsCl coordination number ration is 8:8 (8)
a. AB6 b. AB4 c. AB8 d. AB24 Ans. b (53)
a. a b. a/2 c. √3a/2 d. 2a/√3 Ans. c Explanation : As CsCl is body-centred d = √3a/2 (13)
a. NaF b. SrF 2 c. AlCl 3 d.SiF4 Ans.b Explanation : SrF 2 has fluorite type structure. (8)
a. 2√2a b. √2a c.a / √2 d. 2a Ans. c (5)
9 x 103 kg m-3 forms face centred cubic crystals of edge length 200 √2 pm. What is the molar mass of of the solid a. 0.0432 kg mol -1 b. 0.0305 kg mol -1 c. 0.4320 kg mol-1 d. 0. 0216 …
a. 4 b. 8 c. 12 d. 6 Ans. b Explanation : Body centered cubic lattice has a coordination number 8. (11)
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 which is shared by four adjacent unit cells d. 8 tetrahedral voids …