# Physical Chemistry IV

(Back) Paper: XVIII

* PHYSICAL CHEMISTRY * M. Marks: 50

**Atomic Structure:**

Postulates of quantum mechanics, quantum mechanical operators, Schrodinger equation and its application to particle in a box (rigorous treatment) energy levels, wave functions, probability distribution functions, nodal properties, degeneracy; qualitative treatment of (i) rigid rotator, (ii) harmonic oscillator, (iii) hydrogen atom, (iv) electron spin and (v) multielectron atoms.

**Chemical Bonding:**

Covalent bonding, statement of variation theorem, valence bond and molecular orbital approaches, LCAO-MO treatment of H molecule ion and H molecule, valence bond treatment of H molecule, localised and nonlocalised molecular orbitals of homonuclear, heteronuclear diatomic and triatomic (BeH , H O, CO ) molecules.

**Electrical and magnetic properties**:

Electrostatics of dielectric media, Clausius-Mosotti equation, Lorenz-Lorentz equation, measurement of dipole moment and molecular poalrisability. Magnetic susceptibility, its measurement and molecular interpretation.

**Molecular Structure:**

Molecular Spectroscopy: Interactions of electromagnetic radiation with molecules and various types of spectra; Born-Openheimer approximation.

Rotation spectroscopy: Rotational term (F), intensities of spectral lines, determination of bond length of diatomic and linear triatomic molecules, isotopic substitution.

Vibrational spectroscopy: Vibrational terms (G), Classical equation of vibration. vibrational energies of diatomic molecules, zero point energy. computation of force constant, amplitude of diatomic molecular vibrations. anharmonicity, Morse potential, dissociation energies, fundamental frequencies. overtones, hot bands, degrees of freedom for polyatomic molecules, concept of group frequencies. Vibration-rotation spectroscopy: diatomic vibrating rotator, P,Q,R branches.

Raman spectroscopy: Qualitative treatment of Rotational Raman effect; effect of nuclear spin, Vibrational Raman spectra, Stokes and anti-Stokes lines; their intensity difference, rule of mutual exclusion principle..

Electronic spectroscopy: Franck-Condon principle, electronic transitions, singlet and triplet states, fluorescence and phosphorescence, dissociation and predissociation, calculation of electronic transitions of polyenes using free electron model.

Nuclear Magnetic Resonance (NMR) spectroscopy: Principle of NMR. Larmor-precession, chemical shift and low resolution spectra, different scales, spin-spin coupling and high resolution spectra, interpretation of PMR spectra of A-X type organic molecules.

Electron Spin Resonance (ESR) spectroscopy: its principle, hyperfine structure, ESR of simple radicals.

**Structures of condensed phases**

Nature of the solid state, law of constancy of interfacial angles, law of rational indices, Miller indices, elementary ideas of symmetry, symmetry elements, and symmetry operations, qualitative idea of point and space groups, Seven crystal systems and fourteen Bravais lattices; X-Ray diffraction, Bragg's equation, a simple account of rotating crystal method and powder pattern method Analysis of powder diffraction patterns of NaCl, CsCI and KCI.