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12th Chemistry_Solid State_Avanti Module

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Description: 12th Chemistry_Solid State_Avanti Module

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C15 – Solid State 1 Fifth Edition C15. Solid State TABLE OF CONTENTS C15. Solid State 1 C15.1 Introduction to Solid State ……………………………………………………………………………………………………………2 C15.2 Properties of Solids ………………………………………………………………………………………………………………..……7 Test Practice Problems …………………………………………………………………………………………………………………...……12 Answer Key ………………………………………………………………………………………………………………………………….….…..17

C15 – Solid State 2 C15.1 Introduction to Solid State CONCEPTS 1. Classification of solids 2. Crystal Lattice and Unit Cell 3. Effective number of atoms and coordination number in various unit cells 4. Closed pack structures and voids PRE-READING (30 MINS) You may refer to the following source: Category Book Name (Edition) Chapter Section REQUIRED NCERT XII (Part I) 1 1.1 to 1.6 SYNOPSIS 1. 2. Intermolecular forces Properties Examples Type of solid a. Ion-ion forces i. Brittle, hard, high melting p. ������������������������, ������������������, ������������������������2 b. Dispersion forces q. ������2������, ������������2, ������������2 1. Ionic ii. Soft ,low melting, non- 2. Molecular c. Covalent bonds conducting r. ������-Diamond, ������������������2 d. Metallic bonds s. ������������, ������������, ������������, ������������ 3. Covalent iii. Hard, high melting 4. Metallic iv. Variable hardness and melting point C15.1

C15 – Solid State 3 3. Bravais lattice Intercepts Crystal angles Crystal system Primitive, face centered, ������ = ������ = ������ ∝= ������ = ������ = 90° body centered ∝= ������ = ������ = 90° Cubic Primitive, face centered, ������ ≠ ������ ≠ ������ body centered, end ∝= ������ = ������ ≠ 90° Orthorhombic centered ������ = ������ = ������ ∝≠ ������ = 90°, ������ ≠ 90° Primitive ������ ≠ ������ ≠ ������ Rhombohedral ������ ≠ ������ ≠ ������ ������ ≠ ������ ≠ ������ ≠ 90° Monoclinic Primitive, end centered ������ = ������ ≠ ������ ∝= ������ = ������ = 90° Triclinic ������ = ������ ≠ ������ ∝= ������ = 90°, ������ = 120° Tetragonal Primitive Hexagonal Primitive, body centred Primitive 4. ������������������ ������������������ Parameter Simple cubic ������√3/4 ������√2/4 ������ ������/2 2 4 8 12 ������ 1 0.68 0.74 ������. ������������ 6 ������. ������ 0.52 Figure 1 Simple Cubic Figure 2 Body Centered Figure 3 Face Centered 1 5.

C15 – Solid State 4 6. 7. The crystals are bound by plane faces (������), straight edges (������) and an interfacial angle(������). The relationship between these is ������ + ������ = ������ + ������. 8. No. of atoms per unit cell of ������������������ unit = . No. of atoms per unit cell of ������������������ unit = PRE-READING EXERCISE Q1. __________ solids have a sharp melting point. Q2. __________ solids are also called pseudo solids or supercooled liquids. C15.1

C15 – Solid State 5 Q3. Crystalline solids are __________ in nature, that is, some of their physical properties like electrical resistance or refractive index show different values when measured along different directions. Q4. Crystalline solids can be classified on the basis of nature of intermolecular forces operating in them into four categories i.e. __________, __________, __________ and __________ solids. Q5. Solid ������������2 is an example of __________ molecular solid. Q6. __________ solids contain a sea of mobile electrons. Q7. The number of nearest neighbors of a particle in any arrangement is called its __________. IN-CLASS EXERCISE LEVEL 1 Q1. Crystals can be classified into _______ number of primitive unit cells on the basis of their shape. Q2. ______ number of different Bravais lattices are possible. Q3. What is the number of close neighbors in a body centred cubic lattice of identical spheres? Q4. In the close packed structure i.e. (i) HCP and (ii) CCP of a metallic lattice, the number of nearest neighbors of a metallic atom is ________. Q5. Aluminium crystallizes in an FCC lattice, hence the co-ordination number of aluminium metal is _________. Q6. The crystal system of a compound with unit cell dimensions, ������ = 0.387 ������������, ������ = 0.387 ������������ and ������ = 0.504 ������������, and ������ = ������ = 900 and ������ = 1200 is _______. LEVEL 2 Q7. A solid is made of two elements ������ and ������. The atoms ������ are in CCP arrangement while the atoms ������ occupy all the tetrahedral voids. What is the formula of the compound? Q8. A compound is formed by elements ������ and ������. This compound crystallizes in the cubic structure when atoms ������ are at the corners of the cube and atoms ������ are at the centre of the body. What is the simplest formula of the compound? Q9. Considering a hypothetical unit cell such as one atom at body center, six atoms at corners and four atoms at edge centers, find the total number of atoms belonging to the unit cell. Q10. An alloy of copper, silver and gold is found to have copper constituting the CCP lattice. If silver atoms occupy the edge centres and gold is present at body centre, what will be the formula of the alloy? HOMEWORK LEVEL 1 Q1. A crystalline solid: A) Changes abruptly from solid to liquid when heated B) Has no definite melting point C) Has an irregular 3-dimensional arrangement D) Undergoes deformation of its geometry easily Q2. Which of the following is a non-crystalline solid? A) ������������������������ B) ������������������������ C) ������������������2 D) Glass

C15 – Solid State 6 Q3. An FCC unit cell of aluminum contains the equivalent of how many atoms? Q4. A solid is made of two elements ������ and ������. The atoms of ������ are in CCP arrangement while the atoms of ������ occupy all the octahedral sites. What is the formula of the compound? Q5. If the number of atoms per unit cell in a crystal is 2, the structure of crystal is: A) Simple cubic B) Body centred cubic (BCC) C) Octahedral D) Face centred cubic (FCC) Q6. In a face centred cubic cell, an atom at the face contributes to the unit cell: A) 1 ������������������������ B) 1 ������������������������ C) 1 ������������������������ 2 4 D) 1 ������������������������ 8 Q7. What is the number of atoms/molecules contained in one body centred cubic unit cell of a monoatomic substance? LEVEL 2 Q8. An ionic compound has a unit cell consisting of ������ ions at the corners of a cube and ������ ions on the centres of the faces of the cube. What would be the empirical formula for this compound? Q9. For a hypothetical unit cell, considering 4 atoms at corners, 4 atoms at face centres, 4 atoms at edge centres. Find the total number of atoms in the unit cell. Q10. Match the crystal type from Column I to its Axial ratio in column II Column I(Crystal) Column II (Axial ratio) A) Tetragonal P) ������ ≠ ������ ≠ ������, ������ = ������ = ������ = 90° B) Orthorhombic Q) ������ = ������ ≠ ������, ������ = ������ = ������ = 90° C) Monoclinic R) ������ ≠ ������ ≠ ������, ������ ≠ ������ ≠ ������ ≠ 90° D) Triclinic S) ������ ≠ ������ ≠ ������, ������ = ������ = 90° ≠ ������ Q11. In a CPS (close packed structure) of mixed oxides, it is found that lattice has ������2− (oxide ions), and one-half of octahedral voids are occupied by trivalent cations (������3+) and one-eighth of tetrahedral voids are occupied by divalent cations (������2+). Derive formula of the mixed oxide. C15.1

C15 – Solid State 7 C15.2 Properties of Solids CONCEPTS 1. Packing Efficiency for different types of solids 2. Density of a crystal 3. Bragg’s Law 4. Different types of defects in a crystalline solid 5. Classification of solids on the basis of their Electrical and Magnetic Properties PRE-READING (30 MINS) You may refer to the following source: Category Book Name (Edition) Chapter Section REQUIRED NCERT XII (Part I) 1 1.7 to 1.11 SYNOPSIS 1. 2. The density of a unit cell is given by ������ = ������������������������������������. Here, M is molecular mass. z is number of atoms per unit cell. N0 is the Avogadro’s number. a is the edge length of the unit cell.

C15 – Solid State 8 3. Bragg’s equation is given by ������������ ������������������ ������ = ������������ 1st order reflection: 2������ sin ������ = ������ 2nd order reflection: 2������ sin ������ = 2������ ⇒ ������ sin ������ = ������ 4. 5. The no. of octahedral and tetrahedral voids in a unit cell containing ������ atoms per unit cell is ������ & ������������. 6. 7. The number (������) of defects per ������������3 is given by ������ = ������ × ������−������/������������������. Here, N is the total number of atoms present in the solid. W is the work done or the energy required to create a defect. R is the Universal Gas Constant. T is the absolute temperature. 8. Packing fraction= .������×������������������������������ ������������������������������ ������������������������ Here Z=number of atoms (ions) per unit cell Also note that the units of ������������������������������ and ������������������������������ ������������������������ are the same . C15.2

C15 – Solid State 9 9. Packing Co-ordination no. Location of particle Name of structure ������������������ ������������+ = ������������− = 6 ������−: ������������������ lattice; ������+: Octahedral void. ������������������ ������������2+ = ������2− = 4 ������2−: ������������������ lattice; ������������2+: Alternate 1. Rock salt (������������)������������������������ tetrahedral void 2. Zinc blende (������������������) ������������������ ������������+ = ������������− = 8 ������������−:corners of cube; ������������+:cube centre ������������������ ������������2+ = 8 ������������2+: ������������������ lattice; ������−: Tetrahedral void 3. ������������������������ ������− = 4 4. Fluorite (������������2)������������������2 ������������������ ������������+ = 4 ������2−: ������������������ lattice; ������������+: Tetrahedral void ������2− = 8 5. Anti-fluorite (������2������)������������2������ 10. Column II Column I a) Cations in ������������������ and anions in alternate tetrahedral p. 4: 4 type solid voids. b) Cations in simple cubic packing and anions at body q. 8: 8 type solid centre. c) Anions in ������������������ and cations in all tetrahedral voids. r. 4: 8 type solid d) Cations in ������������������ and anions in all octahedral voids. s. 6: 6 type solid 11. a) Ferromagnetic substance b) Antiferromagnetic substance c) Ferrimagnetic substance

C15 – Solid State 10 PRE-READING EXERCISE Q1. __________ is the percentage of total space filled by the particles. Q2. __________ are the irregularities or deviations from ideal arrangement around a point in a crystalline substance. Q3. Solids with conductivities ranging between 104 to 107������ℎ������−1������−1 are called ___________. Q4. A conductor may conduct electricity through movement of __________ or _________. Q5. Electrical conductivity in semiconductors ___________ (increases/decreases) with increase in temperature. IN-CLASS EXERCISE LEVEL 1 Q1. The packing efficiency of the two dimensional square unit cell shown below is _________. l Q2. Calculate the percentage of free space in cubic close packed (CCP) structure and in body centred packed (BCC) structure. Q3. A metal crystallizes in a BCC lattice. Its unit cell edge length is about 300 ������������ and its molar mass about 50 ������������������������−1. What would be the density of the metal (in ������������������−3)? Q4. Which one of the following defects in the crystals lowers its density? A) Frenkel defect B) Schottky defect C) Interstitial D) None of these Q5. The first order reflection (������ = 1) from a crystal of the ������ −ray from a copper anode tube (������ = 1.54 Å) occurs at an angle of 45°. What is the distance between the set of planes causing the diffraction? LEVEL 2 Q6. The cubic unit cell of ������������ (Molar Mass = 27 ������ ������������������−1) has an edge length of 405 ������������. Its density is 2.7 ������ ������������−3. The cubic unit cell is A) Face centred B) Body centred C) Primitive D) None of these Q7. In an orthorhombic unit cell, the value of ������, ������ and ������ are 6.7 Å, 10.0 Å and 5.0 Å respectively. Given the molecular mass of the solute is 155 ������ ������������������−1and density is 3.1 ������/������������, determine the number of formula units per unit cell. Q8. The composition of a sample of Wustite is ������������0.93������. What is the percentage of iron present as ������������3+ in total iron? (������������ is present as ������������2+ and ������������3+) Q9. An ������������������ lattice has a lattice parameter ������ = 400 ������������. Calculate the molar volume of the lattice including all the empty spaces. A) 10.8 ������������ B) 96 ������������ C) 8.6 ������������ D) 9.6 ������������ C15.2

C15 – Solid State 11 HOMEWORK LEVEL 1 Q1. A metal has BCC structure and the edge length of unit cell is 3.00 Å. The volume of the unit cell in ������������3 will be __________. Q2. If we mix a pentavalent impurity in a crystal lattice of germanium, what type of semiconductor formation will occur? A) ������ −type B) ������ −type C) Both (A) and (B) D) None of the two Q3. The face centred cubic cell of platinum has an edge length of 0.392 ������������. Calculate the density of platinum (������/������������3). (Atomic weight : ������������ = 195 ������������������) Q4. The diffraction of barium with X-radiation of wavelength 2.29Å gives a first-order reflection at 30°. What is the distance between the diffracted planes? Q5. Which kind of defect is shown by the given crystal? ������+������������−������+������������−������+������������− ������������−⎕������������−������+⎕������+ ������+������������−⎕������������−������+������������− ������������−������+������������−������+⎕������+ Q6. In a solid lattice, the cation has left its lattice site and is located at an interstitial position, the lattice defect is A) Frenkel defect B) Schottky defect C) F-centre defect D) Valency defect Q7. Electrons in a paramagnetic compound are A) Shared B) Unpaired C) Donated D) Paired LEVEL 2 Q8. A metallic element has a cubic lattice. Each edge of the unit cell is 2Å. The density of the metal is 2.5 ������ ������������−3. What is the number of unit cells in 200������ of metal? Q9. The density of metal ������ (face centred cubic cell) is 10 ������/������������3 at 200������. What is the diameter of the atom? (Atomic weight of ������ = 96 ������������������, ������������ = 6 × 1023) Q10. A certain sample of cuprous sulphide is found to have composition ������������1.8������, because of incorporation of ������������2+ ions in the lattice. What is the mole % of ������������2+ in total copper content in this crystal? (������������ is present as ������������+ and ������������2+) A) 99.8% B) 11.11% C) 88.88% D) None of these

C15 – Solid State 12 Test Practice Problems Purpose: To practice a mixed bag of questions in a speed based format similar to what you will face in entrance examinations. In most entrance examinations, you will get not more than 3 minutes to attempt a question. Hence, you need to be able to attempt a question in less than 3 minutes, and at the end of 3 minutes skip the question and move to the next one. Approach:  Attempt the Test Practice Problems only when you have the stipulated time available at a stretch.  Start a timer and attempt the section as a test.  DO NOT look at the answer key / solutions after each question.  DO NOT guess a question if you do not know it. Competitive examinations have negative marking.  Solve as much as possible within the stipulated time, and then fill the OMR provided at the end of the TPP.  Fill the table at the end of the TPP and evaluate the number of attempts, and accuracy of attempts, which will help you evaluate your preparedness level for the chapter. Q1. Among the following, under which category are iodine crystals placed? A) Ionic B) Covalent crystal C) Molecular crystal D) Metallic crystal Q2. Which of the following statements about amorphous solids is incorrect? A) They melt over a range of temperature B) There is no orderly arrangement of particles C) They do not have a definite heat of fusion D) They are anisotropic Q3. Hexagonal close packed arrangement of ions is described as: A) ������������ ������������ ������ … B) ������������������ ������������������ … C) ������������������������������������ … D) ������������������ ������������������ … Q4. In a face centred cubic lattice, atom ������ occupies the corner positions and atom ������ occupies the face centre positions. If one of B is missing from one of the faces in each unit cell, the formula of the compound is: A) ������������2 B) ������2������3 C) ������2������5 D) ������2������ Q5. Which of the following is not correct for ionic crystals? A) All have a sharp melting point B) Exhibit the property of anisotropy C) They possess high melting point and boiling point D) They are good conductors of electricity in solid state Q6. In the body centred cubic unit cell of closest packed atoms, the radius of atom in terms of edge length ′������′ of the unit cell is A) ������/2 B) ������/√2 C) ������/2√2 D) √3 ������/4 Q7. How many unit cells are present in a cube- shaped ideal crystal of ������������������������ of mass 1.00 ������? [Atomic mass: ������������ = 23, ������������ = 35.5] (Effective number of ������������������������ molecules in one unit cell is 4) A) 5.14 × 1021 B) 1.28 × 1021 C) 1.71 × 1021 D) 2.57 × 1021 T.P.P.

C15 – Solid State 13 Q8. Which one of the following defects does not affect the density of the crystal? A) Schottky defect B) Interstitial defect C) Frenkel defect D) Both (B) and (C) Q9. Which of the following doping will produce p − type semiconductor? A) Silicon doped with arsenic B) Germanium doped with phosphorus C) Germanium doped with aluminum D) Silicon doped with phosphorus Q10. Which of the following metal oxides is antiferromagnetic in nature? A) ������������������ B) ������������������2 C) ������������2 D) ������������������2 Q11. In the closest packing of atoms, there are: A) One tetrahedral void and two octahedral voids per atom B) Two tetrahedral voids and one octahedral void per atom C) Two of each tetrahedral and octahedral voids per atom D) One of each tetrahedral; and octahedral void per atom Q12. In ������������������������, the silver ion is displaced from its lattice position to an interstitial position. Such a defect is called a A) Schottky defect B) Frenkel defect C) Metal excess defect D) F-centre Q13. Considering ������������������������ shows Schottky defects and ������������������������ shows Frenkel defects. Their electrical conductivities in the solid state are due to the A) Motion of ions and not the motion of electrons B) Motion of electrons and not the motion of ions C) Lower coordination number of ������������������������ D) Higher coordination number of ������������������������ Q14. Amorphous solids may be classified as: A) Isotropic and supercooled liquids B) Anisotropic and supercooled liquids C) Isoenthalpic and superheated liquids D) Isotropic and superheated solids Q15. In silicon crystal, silicon atoms constitute FCC where four out of 8 tetrahedral voids are also occupied by ������������ atoms. The total number of effective atoms in a unit cell is A) 1 B) 2 C) 4 D) 8 Q16. Which of the following exists as covalent crystals in the solid state? A) Phosphorus B) Iodine C) Silicon D) Sulphur Q17. The theoretical density of sodium chloride crystal is 2.2 × 103 ������������ ������−3 while its density calculated using X-ray is 2.195 × 103������������ ������−3. The fraction of the unoccupied sites in sodium chloride crystal is A) 2.27 B) 2.27 × 10−2 C) 2.27 × 10−1 D) 2.27 × 10−3 Q18. The fraction of the total volume occupied by the atoms present in a simple cube is A) π B) π C) π D) π 4 6 3√2 4√2 Q19. Perovskite, a mineral of titanium is found to contain calcium atoms at the corners, oxygen atoms at the face centres and titanium atoms at the centre of the cube. Oxidation number of titanium in the mineral is A) +2 B) +3 C) +4 D) +1 Q20. The number of tetrahedral voids in the unit cell of a face centred cubic lattice of similar atoms is A) 4 B) 6 C) 8 D) 12 Q21. Structure of a mixed oxide is cubic close packed (C. C. P). The cubic unit cell of mixed oxide is composed of oxide ions. One fourth of the tetrahedral voids are occupied by divalent metal ������ and the octahedral voids are occupied by a monovalent metal ������. The formula of the oxide is: A) ������2������3������4 B) ������������2������2 C) ������������������2 D) ������2������������2

C15 – Solid State 14 Q22. A metal crystallizes with a face- centred cubic lattice. The edge of the unit cell is 408 ������������. The diameter of the metal atom is A) 288 ������������ B) 408 ������������ C) 144 ������������ D) 204 ������������ Q23. Edge length of a cube is 400 ������������, its body diagonal would be A) 500 ������������ B) 600 ������������ C) 566 ������������ D) 693 ������������ Q24. A metal has an FCC lattice. The edge length of the unit cell is 404 ������������. The density of the metal is 2.72 ������ ������������−3. The molar mass of the metal is (������������, Avogadro′s constant = 6.02 × 1023 ������������������−1) A) 40 ������ ������������������−1 B) 30 ������ ������������������−1 C) 27 ������ ������������������−1 D) 20 ������ ������������������−1 Q25. The number of atoms in 100 ������ of an FCC crystal with density = 10.0 ������/������������3 and cell edge of 200 ������������ is equal to A) 5 × 1024 B) 5 × 1025 C) 6 × 1023 D) 2 × 1025 Q26. Ice crystallizes in a hexagonal lattice having a volume of the unit cell as 132 × 10−24 ������������3. If density of ice at the given temperature is 0.92 ������ ������������−3 then number of ������2������ molecules per unit cell is A) 1 B) 2 C) 3 D) 4 Q27. If ������������������������ is doped with 10−4������������������ % of ������������������������2, the concentration of cation vacancies will be (������������ = 6.02 × 1023������������������−1) A) 6.02 × 1014������������������−1 B) 6.02 × 1015������������������−1 C) 6.02 × 1016������������������−1 D) 6.02 × 1017������������������−1 Q28. Experimentally it was found that a metal oxide has formula ������0.98������. Metal ������ is present as ������2+ in its oxide. Fraction of the metal which exists as ������3+ would be A) 5.08% B) 7.01% C) 4.08% D) 6.05% Q29. Which of the following is not true about hexagonal close packing? A) It has a coordination number of 6 B) It has 26% empty space C) It is ABAB … type of arrangement D) It is more closely packed than body centred cubic packing. Q30. The empty space in a HCP unit cell is A) 74% B) 47.6% C) 32% D) 26% Q31. Column II (Formula) Column I(Distribution of particles X and Y) A. X= At the corners P. XY Y =At face centres B. X=At the corners and face centres Q. XY2 Y =In all tetrahedral voids C. X=At the corners R. XY3 Y =One on each face centre and body centre D. X=At the corners and face centres S. XY4 Y =At the edge centres and body centre A) A − R, B − Q, C − P, D − S B) A − S, B − P, C − R, D − Q C) A − Q, B − R, C − P, D − S D) A − R, B − Q, C − S, D − P T.P.P.

C15 – Solid State 15 Q32. Column I(Position of particles X and Y) Column II (Formula) P) XY A) X = in cubic close packing Y = in tetrahedral voids B) X = in cubic close packing Q) X3Y2 Y = in octahedral voids C) X = in cubic close packing R) X2Y Y = in alternate octahedral voids D) X = in hexagonal close packing S) XY2 Y = in 2/3 rd of octahedral voids B) A − Q, B − P, C − S, D − R A) A − P, B − Q, C − R, D − S D) A − S, B − P, C − R, D − Q C) A − R, B − S, C − P, D − Q Q33. Column II (Effect) Column I (defect) A. Schottky defect P. Crystal becomes colored B. Doping silicon with aluminum Q. ������-type semiconductor is formed C. Doping silicon with arsenic R. ������ − type semiconductor is formed D. Heating ������������������������ crystal in presence of sodium vapour S. Density of the crystal decreases A) A − S, B − Q, C − R, D − P B) A − Q, B − P, C − R, D − S C) A − Q, B − P, C − R, D − S D) A − S, B − R, C − Q, D − P Q34. Column II (Magnetic nature) Column I (Substance) A. Ferrites P. Ferromagnetic B. ������������������2 Q. Paramagnetic C. Nitric oxide(������������) R. Ferrimagnetic D. Manganese oxide (������������������) S. Antiferromagnetic A) A − R, B − Q, C − P, D − S B) A − R, B − P, C − Q, D − S C) A − R, B − S, C − Q, D − P D) A − S, B − P, C − R, D − Q Q35. Analysis show that nickel oxide consists of nickel ion with 96% ions having oxidation state +2 and 4% having oxidation state +3. Which amongst the following best represent the formula of the oxide? A) ������������1.02������1.00 B) ������������0.96������1.00 C) ������������0.98������0.98 D) ������������0.98������1.00 Q36. If the lattice parameter of ������������ = 5 Å and the mass of ������������ atom is 28 × 1.66 × 10−27 ������������, the density of silicon in ������������������−3 is: (given: silicon has diamond cubic structure where the carbon atoms form the CCP or FCC lattice and alternate tetrahedral voids are also occupied by the carbon atoms) A) 2974 B) 1487 C) 3445 D) 1673

C15 – Solid State 16 DATA ANALYSIS Guide A # of questions Total problems in TPP B # Attempts Total attempts in OMR C # Correct Total questions correct D # Incorrect Out of the ones marked in OMR E # Unattempted ������ − ������ F Percentage attempts ������ G Percentage Accuracy ������ × 100 ������ ������ × 100 Question type # Correct (C) # Incorrect (I) # Unattempted (U) Easy Medium Hard Tip: To begin with, your accuracy must be high, typically > 60%. Percentage attempts should be > 50% As time progresses, your percentage attempts should increase without a reduction in accuracy. Additionally, you should be able to get > 80% Easy questions correct, as they involve basic recall of the concepts and formulae of the chapter. T.P.P.

C15 – Solid State 17 Answer Key C15.1 - INTRODUCTION TO SOLID STATE PRE-READING EXERCISE Q8. ������������ Q1. crystalline Q9. 2.75 Q2. amorphous Q10. ������������4������������3������������ Q3. anisotropic HOMEWORK Q4. Molecular, ionic, metallic, covalent LEVEL – 1 Q5. polar Q1. A Q6. Metallic Q2. D Q7. coordination number Q3. 4 IN-CLASS EXERCISE Q4. ������������ LEVEL – 1 Q5. B Q1. 7 Q6. B Q2. 14 Q7. 2 Q3. 8 Q4. 12 LEVEL – 2 Q5. 12 Q8. ������������3 Q9. 3.5 Q6. Hexagonal Q10. A-Q, B-P, C-S, D-R LEVEL – 2 Q11. ������2������������4 Q7. ������2������ C15.2 – PROPERTIES OF SOLIDS PRE-READING EXERCISE Q5. 1.089 Å Q1. Packing Efficiency Q2. Point defects LEVEL – 2 Q3. Conductors Q6. A Q4. Electrons, ions Q7. 4 Q5. Increases Q8. 15.05%. Q9. D IN-CLASS EXERCISE HOMEWORK LEVEL – 1 LEVEL – 1 Q1. 78.54% Q1. 2.7 × 10−23������������3 Q2. 26%, 32% Q2. B Q3. 6.15 ������/������������3 Q3. 21.5 g/cm3 Q4. B Q4. 2.29Å

C15 – Solid State 18 Q5. Schottky defect LEVEL – 2 Q6. A Q8. 1.0 × 1025 Q7. B Q9. 0.282 ������������ Q10. B TEST PRACTICE PROBLEMS Q. No. Ans. Level Mark (C) / (I) / (U) Q. No. Ans. Level Mark (C) / (I) / (U) as appropriate as appropriate Q1. C Easy Q19. C Medium Q2. D Easy Q20. C Easy Q3. A Easy Q21. B Medium Q4. C Medium Q22. A Medium Q5. D Easy Q23. D Easy Q6. D Easy Q24. C Medium Q7. D Medium Q25. A Medium Q8. C Easy Q26. D Medium Q9. C Easy Q27. D Hard Q10. A Medium Q28. C Medium Q11. B Easy Q29. A Easy Q12. B Easy Q30. D Easy Q13. A Easy Q31. D Medium Q14. A Easy Q32. D Medium Q15. D Medium Q33. D Medium Q16. C Easy Q34. B Hard Q17. D Medium Q35. D Hard Q18. B Medium Q36. A Medium Ans.


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