II B.Tech I Semester Supplimentary Examinations, February 2008
THERMODYNAMICS AND KINETICS
(Metallurgy & Material Technology)
1. (a) Define and explain the following :
i. Critical temperature of a gas.
ii. Critical pressure of a gas
iii. Critical volume of a gas.
(b) Dalton’s law
(c) Henrey’s law
(d) Avagadro’s hypothesis
2. (a) State HESS’s law and explain with example.
(b) Calculate the work done by an ideal gas when it expands from 5 bar, 3500 k to bar 3500 k mass of air is 1.0 kg. Expansion is adiabatic.
(c) How would you determine experimentally the heat of formation of a compound? Explain briefly
3. (a) What is entropy and discuss how it is related to the degree of disorder?
(b) Derive the equation for the entropy change in ideal gases for the following processes
i. Adiabatic process
ii. Isothermal process
iii. Isobaric process.
4. (a) Explain the following
i. Phase equilibrium
ii. Chemical equilibrium
iii. Thermal equilibrium
(b) Define and explain the standard free energy change, ΔGO for a reaction, and the Standard free energy of formation ΔGO f ,of a substance.
5. (a) state the third law of thermodynamics and explain how it rationalize the thermo chemical data
(b) What is the meaning of thermodynamically possible process
(c) What are the important deductions of third law of thermodynamics
6. (a) Derive the expression ΔG=RT ln (P2/P1) from the fundamentals
(b) Calculate G for the process:Δ A(s) =Al(l) at 1000K.Given melting point of Al=933K.heat a fusion at melting point: 10.9X103J/Mole Cp=32.5and 29.3 J/Mol.k for solid and liquid respectively.
7. (a) Say true or false the following statements with suitable Explanation. Activity of component can never be greater then unity in a system under equilibrium.
(b) State and explain Troutons rule.
8. (a) Suppose that the absolute rate of a certain process cannot be measured but the ratio of the rates r2/r1, at the two temperatures T2 and T1 can be measured. Find the activation energy of this process in terms of T2 , T1 , and r2/r1.
(b) Distinguish between the molecularity and order of a reaction.