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Chemistry PYQs Topicwise

A small contribution by Nikhil Mishra (CE12)

Atomic and Molecular Structure

Schrodinger equation

Q. What is the significance of Ψ and Ψ^2. (1.5) Q. Write down the Schrodinger wave equation describing various terms involved. (1.5) Q. What is Schrodinger wave equation? (1.5)

Particle in a box solutions and their applications for

conjugated molecules and nanoparticles

Q. For a particle in a one-dimensional box, write the equation for calculating the energy values corresponding to n = 2. (1.5) Q. Give the schrodinger wave equation for a particle in one dimensional box. (1.5) Q. Derive the expression for E and Ψ for a particle in 1-D box. (5) Q. Derive the equation for particles in one dimensional box. (5) Q. Deduce the expression for total energy and normalized wave function for particle mass (m) in 1-D box with length (L) moving with potential V(x) = 0 (0 < x < L), otherwise V(x) = infinite. (5)

Forms of the hydrogen atom wave functions and the

plots of these functions

Molecular orbitals of diatomic molecules and plots of

the multicenter orbitals & Energy level diagrams of

diatomic

Q. Prepare a molecular orbital energy-level diagram for NO, showing clearly how the atomic orbitals interact to form MOs, illustrating with explanation on dierence

Q. Explain crystal field splitting in octahedral complexes. (7) Q. Give three main postulates of CFT. Explain the splitting of d orbitals under octahedral, tetrahedral and square planar ligand field. (1) Q. What is CFSE? Calculate for d5 (H.S.) and d5 (L.S.) including pairing energy (p) in octahedral complexes. (5)

Band structure of solids and the role of doping on

band structures

Q. What is meant by ‘doping’ in a semiconductor? Explain the role of doping on the band structure of solids. (7) Q. What are the intrinsic & extrinsic semiconductors? (1.5) Q. Explain the eect of doping on band structures of solids. (1.5) Q. What is the role of doping on the band structures of solids? (1.5) Q. Briefly explain the role of doping on band structure. (1.5) Q. Draw an energy level diagram for n-type and p-type semiconductors according to Band theory. (1.5)

Spectroscopic techniques and its

application

Q. Define and explain the following terms: (10) (i) Selection rules (ii) Chemical Shift (iii) MRI (iv) Diraction (v) Crystal Field Splitting

Principles of spectroscopy and selection rules

Q. What do you understand about the term “spectroscopy”. Discuss the various selection rules governing spectroscopy. (5)

Electronic spectroscopy

Q. Write down the selection rules for electronic spectroscopy. (1.5) Q. Explain the theory of UV-visible spectroscopy and various types of electronic transitions. (7) Q. What is hypsochromic shift? (1.5) Q. Write a short note on Chemical Shift. (2) Q. Write a short note on Beer-Lambert's Law. (2) Q. Discuss the principle of electronic spectroscopy. Explain with reference to butadiene and carbonyl compounds. (5) Q. Define the following term: Bathochromic shift. (2)

Fluorescence and its applications in medicine

Q. Explain the process of fluorescence using the Jablonski diagram. (5) Q. Write a short note on Fluorescence. (2)

Q. Write a short note on shielding and deshielding of protons in NMR spectroscopy. (5)

Surface characterization techniques

Diraction and scattering

Intermolecular Forces and Potential

Energy Surfaces

Q. What are intermolecular forces? How do they impact the physical properties of matter? (1.5) Q. Give a detailed account for any four intermolecular forces of attraction existing in molecules. (8)

Ionic, dipolar, and van der Waals interactions

Q. What are dipole-induced dipole interactions? (1.5) Q. Derive Van der Waals equation for real gases and extend the derivation to critical phenomenon. (8) Q. Define the following term: Van Der Waals interactions. (2) Q. Define and explain van der waals interactions. (1.5) Q. Explain the following term: London forces. (2)

Equations of state of real gases and critical

phenomena

Q. Define critical temperature. (1.5) Q. Write down the equation of state for real gases. (1.5) Q. Derive the relation between heat of reaction at constant volume and heat of reaction at constant pressure. (1.5) Q. Explain causes of deviation of gases from ideal behavior. (1.5) Q. Explain the following term: Critical Temperature and Compressibility factor. (4)

Potential energy surfaces of H 3 , H 2 F, and HCN

Q. Write a short note on the potential energy surface of the H + H 2 model. (5)

Use of Free Energy in Chemical

Equilibria

Thermodynamic functions: energy, entropy, and free

energy

Estimations of entropy and free energies

Q. How will you predict spontaneity in terms of entropy and free energy? (1.5) Q. What do you understand by the terms entropy and free energy? Explain briefly. (1.5) Q. Define entropy and enthalpy of a reaction. (1.5)

Free energy and emf

Cell potentials, Nernst equation, and applications

Q. Derive Nernst Equation and write down its applications. (7) Q. Derive the Nernst equation and explain its various applications. (7) Q. Give the equation which relates cell potential and Gibbs free energy at equilibrium. Write three main applications of Nernst equation with examples. (8) Q. Define and explain the following terms: Free energy, Entropy. (4)

Acid-base, oxidation-reduction, and solubility

equilibria

Water chemistry

Q. What is meant by the hardness of water? How are they classified? Explain any two methods for softening of hard water. (8)

Q. Give two points how scale and sludge formation can be prevented in boilers. (1.5)

Corrosion

Q. Explain electrochemical corrosion with suitable examples. (1.5) Q. What do you understand about corrosion? Discuss its causes of happening. (5) Q. Give the main dierence between wet and dry corrosion with an example. (1.5) Q. Define and explain the term corrosion. (1.5) Q. What do you mean by corrosion? Explain the factors influencing corrosion. (5) Q. Discuss in brief Wet corrosion and Dry corrosion. (5)

Use of free energy in metallurgy through Ellingham

diagrams

Q. What does an Ellingham diagram signifies? (1.5) Q. Explain Ellingham diagram listing its uses and limitations. (7) Q. Draw a well labeled Ellingham diagram. (5) Q. Using the Ellingham diagram explains metal extraction from its oxide. (5)

Variations of s, p, d, and f orbital energies of atoms

in the periodic table

Electronic configurations

Atomic and Ionic sizes

Ionization energies (Pg. 18)

Q. Dierentiate ionization energy and electron anity. (1.5)

Electron anity

Q. Dierentiate ionization energy and electron anity. (1.5)

Electronegativity (pg. 28)

Q. What do you understand by the term electronegativity? Explain the factors aecting the magnitude of Electronegativity? (2) Q. What do you understand about electronegativity? Explain its variation across the periodic table. How does it aect other properties of elements/molecules? (5) Q. Explain the periodic trend for electronegativity. (4) Q. What is electronegativity? Write the factor aecting the electronegativity. (3) Q. Explain the Allred Rochaw scale of electronegativity. (2)

Polarizability (Pg. 31)

Q. Define the terms polarizing power and polarizability? Also, discuss the fajans rule for ionic and covalent character of a bond? (2) Solution: Polarizing power: The power of cation to polarize an anion is known as polarizing power, it depends on two factors: (i) Charge on cation: bigger the charge, bigger the polarizing power.

(ii) Size of cation: smaller the charge, bigger the polarizing power. Polarizability: The ability of an anion to get polarized is known as polarizability. It depends on two factors: (i) Charge on anion: bigger the charge, more will be the ability to get polarized. (ii) Size of cation: bigger the size, more will be the ability to get polarized.

Higher polarizing power and polarizability = forms strong covalent bonds.

Q. Explain Fajan’s rule of polarizability and its significance. (5) Q. Briefly explain polarization and polarizability. Discuss the factor influencing polarizability and consequences of polarizability. (5) Q. What do you understand about polarizability? How does it polarize power? Discuss the Fajans rule for ionic and covalent character of a bond. (8)

Oxidation states

Coordination numbers

Q. What is the coordination number? Give two examples of complexes having coordination numbers of 2 and 4. Q. Explain in detail on coordination numbers and geometries with examples for each. (5)

Geometries & Molecular geometries

Q. Discuss the geometry of ClO 3 -^ and PCl 5. (5) Q. Give the geometries possible for coordination number 4. Using VSPER theory predicts the shape of a AB 3 molecule having 2 lone pairs of electrons on central atom A. (5)

Hard soft acids and bases

Q. Dierentiate between hard and soft acids? (1.5, 2) Q. What is the dierence between hard acid and soft acid with an example?

Stereochemistry

Q. Define the following terms: (10) (i) Geometrical isomerism (ii) Optical Activity (iii) Absolute configuration (iv) Fischer projection (v) Chiral center

Representations of 3-dimensional structures

Q. Draw the Fischer projection formula for (2R) - 2 - Bromobutane. (1.5)

Structural isomers and stereoisomers

Q. Discuss taking examples of organic molecules types of structural and stereoisomerism. (5)

Configurations

Q. Explain the dierence between conformational and configurational isomers? (1.5)

Symmetry and Chirality

Q. Explain the symmetry operations existing in square planar [PtCl 4 ] 2-

. (2) Q. Define the following terms: (i) Chirality (ii) Chiral Axis (4) Q. Define and explain the following term: Symmetry elements. (2) Q. Define Chirality and explain how it leads to the phenomenon of optical activity. (1.5)

Enantiomers, Diastereomers

Q. Dierentiate between the following pairs with suitable examples of each - (i) Enantiomers and diastereomers. (ii) Racemic mixture and meso compounds. (5) Q. What do you mean by meso compounds? Explain using suitable examples. (1.5) Q. Give examples for (i) Enantiomers (ii) Diastereomers (iii) Metamers (iv) Conformational isomers. (5)

Q. Dierentiate between enantiomers and diastereomers. (1.5) Q. Why do enantiomers have the same physical and chemical properties while diastereomers have dierent? (1.5) Q. What are Anomers? (2) Q. Indicate the following compounds as enantiomers/diastereomers/identical or none. (9) Q. Indicate the following compounds as enantiomers / diastereomers / identical or none.

Q. Explain the structural isomerism in transition metal compounds with suitable examples. (5) Q. Discuss stereoisomerism in transitional metal compounds with suitable examples. (5) Q. Discuss the dierent types of isomerism possible in transition metal compounds. (5) Q. Discuss the dierent types of structural isomers in transition metal complexes with suitable examples. (5) Q. What do you understand about the term epimerism? Explain briefly giving suitable examples. (1.5)

Organic Mechanism and Synthesis of a

Drug Molecule

Substitution

Q. Explain Nucleophilic substitution reactions? Dierentiate between SN1 and SN2. (3) Q. Explain the types, mechanisms and factors aecting Nucleophilic substitution reactions? (4) Q. Explain the mechanism of Nucleophilic bimolecular substitution reaction with an example. (1.5) Q. Define Walden Inversion. (1.5)

Q. Explain elimination reaction with detailed mechanism by taking suitable examples along with rules governing major product formation. Describe how elimination reaction competes with substitution reaction. (8) Q. Allyl halides rapidly undergo nucleophilic substitution reactions while vinyl halides do not. Explain. (1.5) Q. Nucleophilic substitution and elimination reactions often compete with each other. Justify this statement giving the conditions when substitution is preferred over elimination. (5) Q. Define and explain briefly the term racemisation. (1.5) Q. Why does benzene undergo electrophilic substitution rather than addition reaction? (1.5) Q. Write the dierence between SN1 and SN2 reactions. (1.5)

Addition

Q. Why does benzene undergo electrophilic substitution rather than addition reaction? (1.5) Q. What is diel’s Alder cycloaddition reaction? Explain with at least one example. (3) Q. Give the Wurtz method for the preparation of alkane. (1.5)

Elimination

Q. Give examples for elimination reactions and compare the E1 and E2 reactions mechanisms. (7) Q. Explain elimination reactions with detailed mechanisms by taking suitable examples along with rules governing major product formation. Describe how elimination reaction competes with substitution reaction. (8) Q. Nucleophilic substitution and elimination reactions often compete with each other. Justify this statement giving the conditions when substitution is preferred over elimination. (5)