JNTU B.Tech I Semester Regular Examinations, November 2008
METALLURGICAL THERMODYNAMICS AND KINETICS
(Metallurgy & Material Technology)
1. (a) An open system defined for a fixed region and a control volume are synonyms.
(b) Define and explain an ‘isolated system’.
(c) What is a Thermodynamic cycle? Explain with examples. [6+4+6]
2. (a) Explain what is a reversed heat engine?
(b) What are the two statements known as Carnot principles. State and explain them.
(c) A cyclic process yields 100 KJ of work. When 50 KJ of heat is being transferred
to the heat sink, find the thermal efficiency of the cycle.
3. (a) Prove that Gibb’s free energy and Helmholtz free energies are functions of state.
(b) A container having 3 compartments contains 1 mole of gas A, 2 moles of gas B and 3 moles of gas C at same temperature, presssure (298 K and 1 atm). The partitions are lifted and gases are allowed to mix. Calculate the change in Gibb’s free energy (Assume the gases behave ideally).
4. (a) Derive the expression: ln _P2
P1_ = ?_HV
R _ 1
(b) Explain Duhringes rule for the estimation of the vapour pressure of an element
with suitable examples.
5. (a) What are the macroscopic laws of diffusion? Explain?
(b) Explain how the oxidation of a metal is controlled by the diffusion rate of atoms (or ions) through the surface layer.
6. (a) Describe the relation between temperature and pressure for a univariant equilibrium in a binary system?
(b) Explain the significance of breaks in the plot of free energy of formation against temperature?
7. (a) Explain about the elevation of boiling point by a non-volatile solute?
(b) Discuss about depression of freezing point and is applicable to a liquidus line?
8. Explain about the effect of concentration on the reaction rate:
(a) First order reaction
(b) Second order reaction
(c) Third order or higher order reaction.