PYQ Solutions

Every question below is solved in full inside its chapter's PYQ Zone — this page is your finder. We read all 50 pages of the new B.Sc. papers (CC-6, CC-9, CC-11, DSE-1, DSE-4 · 2018–2025) plus all 60 pages of the M.Sc. papers (MSCH/MCHEM · 2020–2024) with AI vision, and kept only the questions that belong to the Structure and Properties of Solids syllabus. Each entry shows the exact year, B.Sc./M.Sc. paper, question number and marks; questions that repeated across years say so.

• Q1(e) — “What are the dimensional characteristics of a triclinic Bravais lattice?”
  2024 · B.Sc. DSE-1 · 2 marks
• Q1(a) — “Name the different types of Bravais lattices that can be obtained for a tetragonal crystal. Find the number of atoms per unit cell for a body-centred tetragonal crystal.”
  2023 · B.Sc. DSE-1 · 2 marks
• Q2(a)(i) — “Five-fold rotational axis of symmetry is impossible in case of a crystal. Justify.”
  2019 · B.Sc. DSE-1 · 3 marks
• Q2(b)(ii) — “By means of lattice diagram, show the possible Bravais lattices in case of an orthorhombic system of crystals.”
  2019 · B.Sc. DSE-1 · 2 marks
• Q2(a)(i) — Justify or criticize: “Miller indices of a crystal face actually refer to a class of faces.”
  2024 · B.Sc. DSE-1 · 2 marks
• Q2(a)(ii) — “Find the intercepts made on the three axes by the first (most near to the origin) two planes among the class represented by the Miller indices (2̄10). Depict the two planes.”
  2024 · B.Sc. DSE-1 · 3 marks
• Q10(b) — “Designate the Miller indices of all the six faces of a simple cubic unit cell with appropriate diagram.”
  2021 · B.Sc. DSE-1 · 5 marks
• Q3(c)(ii) — “Find out the intercepts on the crystallographic axes of a plane with Miller indices (2 0 1) with unit cell dimensions a = 6·8 nm, b = 8·6 nm and c = 4·6 nm.”
  2022 · B.Sc. DSE-1 · 2 marks
• Q3 — “Calculate the percentage of void space in a fcc unit cell. Find out the Miller indices of the plane that makes intercepts ½, 2 and 3/2 multiples of unit distances on the three axes.”
  2020 · B.Sc. DSE-1 · 5 marks
• Q2 — “Derive the expression of interplanar distance for an orthorhombic system. Calculate the coordination number of an atom in 3-D close packed structure.”
  2020 · B.Sc. DSE-1 · 5 marks
• Q1(c) — “Find the symmetry elements and operations of a cube.”
  2022 · M.Sc. MSCH-104 · 3 marks
• Q3(a)(i) — “Derive the Bragg's equation of diffraction of X-ray on a crystal. State the condition for the validity of this equation.”
  2023 · B.Sc. DSE-1 · 3 marks
• Q3(a)(ii) — “In X-ray diffraction, KCl shows SC pattern though it is a FCC lattice. — Comment.”
  2023 · B.Sc. DSE-1 · 2 marks
• Q3(a)(i) — “Explain why a crystal acts as a three-dimensional diffraction grating for X-rays.”
  2024 · B.Sc. DSE-1 · 2 marks
• Q3(a)(ii) — “What do you mean by order of reflection? What is its significance?”
  2024 · B.Sc. DSE-1 · 2 marks
• Q3(a)(iii) — “Find the minimum interplanar distance for a crystal to produce a diffraction spectra for a given radiation.”
  2024 · B.Sc. DSE-1 · 2 marks
• Q1(f) — “What is the minimum measurable value of spacing between crystal planes when the wavelength of 1·67 Å is employed?”
  2022 · B.Sc. DSE-1 · 2 marks
• Q1(h) — “Why are radio waves considered to be unsuitable for determining crystal structure?”
  2022 · B.Sc. DSE-1 · 2 marks
• Q2(a)(i) — “The molar volume of KCl is 1·3 times that of NaCl. The glancing angle for the 1st order Bragg reflection from the (200) plane of NaCl is 5·9°. Find the glancing angle from the (200) plane of KCl.”
  2023 · B.Sc. DSE-1 · 3 marks
• Q3(b) — “Determine the highest order of reflection that can be observed in Bragg's reflection from a solid employing X-ray spectroscopic technique.”
  2021 · B.Sc. DSE-1 · 5 marks
• Q1(f) — “Show that the interplanar distance for a cubic crystal can never be a/√7, where 'a' is the length of an edge of the cube.”
  2024 · B.Sc. DSE-1 · 2 marks
• Q2(d)(i) — “Show that the distance of separation between the successive (hk) planes in a two dimensional square lattice is a/√(h²+k²), where 'a' is the unit distance along X and Y axes.”
  2019 · B.Sc. DSE-1 · 3 marks
• Q3(b)(ii) — “A metal forms a cubic lattice with edge length 6·18 Å. Find the radius of an atom of the metal (taking an atom to be spherical) if the density of the metal be 1·87 g cm⁻³ & the mass of one atom of it be 132·9 a.m.u.”
  2024 · B.Sc. DSE-1 · 4 marks
• Q3(b)(iii) — “Aluminium (At. wt. 27, density 2·69 g cm⁻³) crystallises with FCC lattice. What is the distance of closest approach of Al-atoms in the crystal?”
  2023 · B.Sc. DSE-1 · 3 marks
• Q3(d)(i) — “Ag is known to crystallise in f.c.c. form and the distance between the nearest neighbour atoms is 2·87 Å. Calculate the density of Ag [At. Wt. of Ag = 108].”
  2022 · B.Sc. DSE-1 · 3 marks
• Q3(a) — “Europium (Atomic weight: 152 g·mol⁻¹) crystallizes in a bcc lattice. The density of Europium (Eu) is estimated to be 5.26 g·cm⁻³. Calculate the radius of Eu atom from above information.”
  2021 · B.Sc. DSE-1 · 5 marks
• Q3(c)(i) — “Insulin forms crystals of orthorhombic type with a = 13 nm, b = 7·48 nm and c = 3·09 nm. If the density of the crystal is 1·315 × 10³ kg/m³, and there are 66 insulin molecules per unit cell, what is the molar mass of insulin?”
  2022 · B.Sc. DSE-1 · 3 marks

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• Q1(b) — “Mention two differences between tetrahedral void and octahedral void.”
  2023 · B.Sc. DSE-1 · 2 marks
• Q2 — “What is the key difference between hcp and ccp structures? Suppose X atoms form a close packed lattice structure, where Y atoms (smaller than X atoms) have to be incorporated without disturbing the close-packed lattice. Write down the formula of the compounds with proper justification when (i) Y atoms are occupied in all tetrahedral voids; (ii) Y atoms are occupied in half of the tetrahedral voids; (iii) Y atoms are occupied in all the octahedral voids; and (iv) Y atoms are occupied in half of the octahedral voids. Mention the limiting radius in each case of Y atoms in regard to that of X atoms, so that Y atoms fit perfectly either in tetrahedral voids or in octahedral voids.”
  2021 · B.Sc. DSE-1 · 5 marks
• Q3(d)(iv) — “Calculate the packing efficiency of fcc lattice.”
  2018 · B.Sc. CC-6 · 2 marks
• Q2(b)(i) — “Calculate the percentage of space occupied in an atomic BCC lattice.”
  2023 · B.Sc. DSE-1 · 3 marks
• Q2(b) — “What do you mean by radius ratio principle? What information can be obtained from it? Find out the limiting radius ratio for tetrahedral and cubic coordination.”
  2022 · B.Sc. CC-6 · 5 marks

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• Q3(b)(i) — “What do you mean by lattice energy of an ionic crystal? Calculate the lattice energy of NaCl using the following data: Madelung Constant (A) = 1·748, Equilibrium ionic distance = 2·79 Å, Born Exponent = 8·0, Electronic charge = 4·8×10⁻¹⁰ esu.”
  2022 · B.Sc. CC-6 · 4 marks
• Q2(d)(i) — “What is Madelung's constant? What is its significance?”
  2018 · B.Sc. CC-6 · 3 marks
• Q7 — “What is Born-Haber Cycle? Calculate the lattice energy of NaCl crystal from the following data by use of Born-Haber Cycle. Sublimation energy (S) = 108.7 kJ mol⁻¹, Dissociation energy for Cl₂ (D) = 225.9 kJ mol⁻¹, Ionization potential of Na(g) (I) = 489.5 kJ mol⁻¹, Electron affinity of Cl(g) (E) = −351.4 kJ mol⁻¹, Enthalpy of formation of NaCl (ΔHf) = −414.2 kJ mol⁻¹.”
  2021 · B.Sc. CC-6 · 5 marks
• Q7 — “Define lattice energy. Establish Born-Haber cycle for the formation of MgS(s) starting from Mg(s) and S₈(s), and hence calculate the electron affinity of S(g) for the S(g) + 2e⁻ ⟶ S²⁻(g) reaction using the thermochemical data given below: Enthalpy of formation = −345 kJ mol⁻¹, Enthalpy of sublimation of Mg(s) = 153 kJ mol⁻¹, Sum of 1ˢᵗ and 2ⁿᵈ ionization potentials of Mg(g) = 2187 kJ mol⁻¹, Enthalpy of atomization of S₈(s) = 559 kJ mol⁻¹, Lattice energy of MgS(s) = −2948 kJ mol⁻¹.”
  2020 · B.Sc. CC-6 · 5 marks
• Q3(a)(ii) — “Calculate the heat of formation (ΔHf) of KF from its elements from the following data by the use of Born-Haber cycle. Sublimation energy of K(s) = 87·8 kJ mol⁻¹, Dissociation energy of F₂(D) = 158·9 kJ mol⁻¹, Ionization energy of K(g)(I) = 414·2 kJ mol⁻¹, Electron affinity for F(g)(E) = −334·7 kJ mol⁻¹, Lattice energy of KF (U₀) = −807·5 kJ mol⁻¹.”
  2018 · B.Sc. CC-6 · 3 marks

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• Q5 — “What are spinels? Using crystal field model, explain why Fe₃O₄ has an inverse spinel structure while Mn₃O₄ has a normal spinel structure. A complex of a transition metal ion with d⁶ electronic c
  2020 · B.Sc. CC-11 · 5 marks
• Q3(a) — “What type of spinel structure do you expect for Co₃O₄ and NiCr₂O₄? Explain on the basis of CFT.” ⭐⭐⭐
  2021 · B.Sc. CC-11 · 5 marks
• Q2(a)(i) — “Using crystal field stabilization energy (CFSE) indicate spinels to be normal or inverse: Mn₃O₄, Fe₃O₄” ⭐⭐⭐⭐
  2024 · B.Sc. CC-11 · 2+2 marks
• Q3(c)(iii) — “What are pyroxene and amphibole? Illustrate structurally.” ⭐⭐⭐
  2019 · B.Sc. CC-9 · 2 marks

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• Q1(e) — “What are stoichiometric defects? — Give an example.” ⭐⭐⭐⭐⭐
  2018 · B.Sc. CC-6 · 2 marks
• Q6 — “Describe Frenkel and Schottky defects. Discuss the kind of crystal defect observed when ZnO is heated. State the detectable change.” ⭐⭐⭐⭐⭐
  2021 · B.Sc. CC-6 · 5 marks
• Q1(b) — “'ZnO is white when cold but yellow when hot' — Explain.” ⭐⭐⭐⭐⭐
  2022 · B.Sc. CC-6 · 2 marks
• Q9 — “Crystals of H₂O have a residual entropy of 3.35 J K⁻¹mol⁻¹ at 0K – Explain. Lt(Cp−Cv)→0 (T→0) – Establish from 3rd law of thermodynamics.” ⭐⭐⭐⭐⭐
  2021 · B.Sc. DSE-1 · 5 marks
• Q2(d)(ii) — “The residual entropy of carbon monoxide is about 5·76 JK⁻¹mol⁻¹. — Comment.” ⭐⭐⭐⭐⭐
  2019 · B.Sc. DSE-1 · 2 marks
• Q3(c)(i) — “Define 'residual entropy'. Find an expression of Helmholtz function A in terms of partition function.” ⭐⭐⭐
  2019 · B.Sc. DSE-1 · 3 marks (1+2)
• Q5 — “Give the statement of Nernst Heat theorem and explain it. What is residual entropy?” ⭐⭐⭐⭐
  2020 · B.Sc. DSE-1 · 5 marks

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• Q3(b)(i) — “Write about the band theory of metals.” ⭐⭐⭐
  2018 · B.Sc. CC-6 · 4 marks
• Q3(b)(ii) — “What are semiconductors? Give an example of n-type semiconductor.” ⭐⭐⭐⭐
  2018 · B.Sc. CC-6 · 3 marks
• Q1 (second half) — “The electrical conductivity of metal decreases with the rise in temperature but the reverse occurs with semiconductors”-Explain. ⭐⭐⭐
  2021 · B.Sc. CC-6 · 5 marks
• Q6(a) — “Define “density of states(D(E))” and show that it is proportional to (energy)-1/2. Write the expression of D(E) for a zero dimensional solid, one dimensional quantum wire and [two] dimensiona
  2023 · M.Sc. MSCH-104 · 3½+… [unclear]
• Q3(b)(ii) — “Boron nitride has a structure similar to graphite. Yet, graphite is a good conductor of electricity whereas boron nitride is not so.” — Account for this difference. ⭐⭐⭐
  2023 · B.Sc. CC-9 · 2.5 marks
• Q3(d)(i) — “Derive an expression of vibrational partition function for a Planck’s oscillator (classical). Hence arrive at the Einstein’s expression of molar heat capacity of a monatomic solid. Comment
  2019 · B.Sc. DSE-1 · 6 marks (2+2+2)
• Q3(c)(iv) — “State Debye T³ law and mention its utility.” ⭐⭐⭐
  2022 · B.Sc. DSE-1 · 3 marks
• Q10(a) — “Write down the drawback of Einstein’s equation of heat capacity of solids. Mention the main difference between the assumptions of Einstein and that of Debye regarding the vibrations in solid
  2021 · B.Sc. DSE-1 · 5 marks
• Q2(a)(ii) — “Mention one important property of polythiazyl.” ⭐⭐⭐
  2023 · B.Sc. CC-9 · 1 mark

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• Q1(a) — “Exemplify the terms: magnetically dilute and magnetically concentrated substances.” ⭐⭐⭐⭐
  2019 · B.Sc. CC-11 · 2 marks
• Q3(d)(iii) — “What is super exchange phenomenon—state with example.” ⭐⭐⭐⭐⭐
  2023 · B.Sc. CC-11 · 2 marks
• Q3(c)(i) — “Define ferromagnetism and anti-ferromagnetism correlating with the spin exchange coupling constant (J).” ⭐⭐⭐⭐
  2022 · B.Sc. CC-11 · 3 marks
• Q3(d)(iv) — "Give elementary idea on antiferromagnetism with example." ⭐⭐⭐
  2023 · B.Sc. CC-11 · 2 marks
• Q3(c)(ii) — “What do you mean by Curie Point and Neel Point?” ⭐⭐⭐
  2022 · B.Sc. CC-11 · 2 marks
• Q3(c)(iv) — “Comment on the magnetic behaviour of solid AgO.” ⭐⭐⭐⭐
  2022 · B.Sc. CC-11 · 3 marks
• Q3(d)(ii) — “Explain quenching of magnetic moment with example.” ⭐⭐⭐
  2023 · B.Sc. CC-11 · 2 marks
• Q3(c)(i) — “State the SI units of the following: magnetic pole strength, magnetic moment, magnetic permeability, molar susceptibility” ⭐⭐⭐
  2019 · B.Sc. CC-11 · 2 marks (½×4)
• Q1(d) — “Define magnetic double exchange phenomenon.” ⭐⭐⭐
  2022 · B.Sc. CC-11 · 2 marks

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• Q1(f) — “What is Clathrate compound? Give its example.” ⭐⭐⭐
  2022 · B.Sc. CC-9 · 2 marks
• Q3(c)(i) — “Outline the principle of zone refining. Which metals are purified by it?” ⭐⭐⭐⭐
  2019 · B.Sc. CC-9 · 4 marks

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