Atomic Structure and Chemical Bonding — DU B.Sc (hons) Chemistry Previous Year Question Papers

(b) Give the application of lattice energy. Calculate the heat of formation of CsF from its elements using the Born-Haber cycle with the following data: Lattice enthalpy of CsF = +740 kJ/mol' Heat of sublimation of Cs = +76.1 kJ/mol' Electron gain enthalpy of F = -328 kJ/mol' Dissociation energy of F2 = +158 kJ/mol' (c) i) Differentiate between MOT and VBT. ii) Differentiate between lattice energy and salvation energy. (5,5,5) 4. (a) Calculate the percent ionic character of LiF having a bond length of 156 pm and a dipole moment of 6.32D. (b) What is the significance of de-Broglie equation. Give the mathematical expression of normalized and orthogona! Wavefunction. (c) Draw the radial probability of distribution curve of 2s, 3p and 4d. (5,5, 5) 5. (a) Give the limitation of valence bond theory (VBT).Give the shapes of p-orbitals. (b) Write down properties of acceptable wave function. (c) Arrange the following in terms of increasing order of their melting point and explain: LiCI, NaCI,KCI. RbCI, CsCl (5,5, 5) 6. Write Short notes on any three of the following: (a) Radial Probability Distribution (b) Bonding and Antibonding Molecular Orbital (c) VSERP Theory (d) Aufbau Principle (5,5,5)