# JNTU Previous B-Tech Supplementary Examinations,Thermodynamics and Kinetics-Feb-2008

**B-Tech Supplementary Examinations, Feb-2008**

** Thermodynamics and Kinetics**

** (Metallurgy & Material Technology)**

1. (a) Write the statement for four laws of thermodynamics.

(b) Define and explain the standard state of a substance.

(c) Equation of state.

2. (a) Show that internal energy is a function of temperature only.

(b) The internal energy of a closed system is given by U = 100 + 50T+ 0.04T2 in Joules. The heat absorbed Q = 4000 +16T in Joules. ( T is in Kelvin ). If the system changes from 500 K to 1000 K, what did the work done.

(c) Calculate the work transfer and change in internal energy if the gas is changing its state from 1 bar, 270 to 20 bar, 4000 C polytropically.

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) Prove that the change in internal energy Cv dt

(b) Derive Gibbs-Helmholtz equations.

5. (a) What do you know about thermo chemical data.

(b) Discuss the use of third law of thermodynamics in evolution of SO of a reaction.

6. (a) Derive the expression? G=RT ln (P2/P1) from the fundamentals

(b) Calculate ?G for the process: 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) Derive the classius-clapyron equation for liquid vapor equilibrium.

(b) The vapor pressure of a substance A at 34.70C is 100 mmHg and the heat of vaporization of A is 38.6KJ/Mol.what is the vapor pressure at A at 650C? (Data:? Hvap: .6KJ/Mole R=8.3145J/Mo/K)

8. (a) Explain Zero order reaction.

(b) Explain collision theory of chemical reaction.

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