# JNTU Exam Papers,II B.Tech I Semester Supplimentary Examinations,THERMODYNAMICS AND KINETICS,February 2008

## SET-4

1. (a) Name the following systems with proper explanation.
i. A container having water and ice exchanging heat with surroundings.
ii. A system consisting of sugar and water.
iii. A system consisting of air in a closed container.
(b) Bring out the difference among the following.
i. Thermodynamic system
ii. Thermodynamic process
iii. Thermodynamic cycle.

2. (a) Distinguish between reversible , quasi – static ; and spontaneous process.
(b) What is HESS’s law ? Explain its application in thermodynamics with suitable examples.
(c) Does the Joule – Thomson coefficient of a substance change with temperature at a fixed pressure? Explain?

3. (a) Write a critical essay on ‘entropy’ its physical significance the statistical interpretation of entropy and the importance of entropy in thermodynamics. Give suitable example where ever necessary.
(b) The molar heats of formation and the entropies of formation at 298k ,for various oxides of metals ‘M’ and oxygen gas are listed below. From the information provided calculate G298 ; H298 for the reaction .
i. 4Mo(s) + O2(g) ! 2M2O3(s)
ii. 2M2O3 + O2(g) ! 4MO2(s)
iii. 4MO2(s) + O2(g) ! 2M2O5(s)

 Oxide H298 (KJ/Mole of Oxide) H 298(J/K – Mole of Oxide) MO -510.4 -110.7 M2O3 -1495.6 -430.4 MO2 -870.6 -212.6 M2O5 -1850.7 -412.6

4. (a) What are the various factors on which the free energy of substance of a fixed mass depends? Explain them.
(b) Derive all T ds equations from thermodynamic relations.

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) ‘Fugacity of a component is equal to its activity for ideal solution’. Say true or false and explain why is it so.
(b) Derive an expression for the change in the free energy when 1gram mole of a pure substance goes in solution.

7. (a) Derive clausius -clapeyron equation starting from fundamentals. State the condition under which approximation is valid.
(b) Prove that violation of the Kelvin- plank statement leads to violation of the clausius statement of the second law of thermodynamics.

8. (a) Bring out the important characteristics of a catalyst and explain its action.
(b) It is often said that the rate of a typical chemical reaction doubles with every 10 degrees raise in temperature. What must be the activation energy of a reaction for which this statement is true in the vicinity of 300 k?