A car engine takes atmospheric air in at 20°C, no fuel, and exhausts the air at – 20°C producing work in the process. What do the first and the second laws say about that?

Does a reversible process change the availability if there is no work involved? 

Is the reversible work between two states the same as ideal work for the device?  

When is the reversible work the same as the isentropic work? 

Define thermodynamic equilibrium of a system and state its importance. What are the conditions required for a system to be in thermodynamic equilibrium? Describe in brief.
Or
What do you known by thermodynamic equilibrium.

Which of the following reactions has the largest value of ∆S◦ ?

1. K(s) + O₂(g) → KO₂(s) 

2. BaCl₂· 2 H₂O(s) → BaCl₂(s) + 2 H₂O(g)

3. N₂(g) + 3 H₂(g) → 2 NH₃(g)

4. NH₃(g) + HCl(g) → NH₄Cl(s)

5. 2 H₂(l) + O₂(l) → 2 H₂O(g) 

For which of the following processes does the entropy of the universe decrease? 

1. None of these is 

2. melting one mole of ice to water at 0◦C 

3. freezing one mole of water to ice at 0◦C 

4. freezing one mole of water to ice at 0◦C and then cooling it to −10◦C 

5. freezing one mole of water to ice at −10◦C 

For a given reaction, if ∆H°  rxn is (negative/positive/either) and ∆S° rxn is (negative/positive/either), then the value of ∆G° rxn will always decrease as you raise the temperature.

1. either, positive

2. positive, either 

3. either, negative 

4. negative, either 

5. positive, negative 

6. negative, positive

Consider the equation NH₄Br(s) → NH₃(g) + HBr(g) carefully, and think about the sign of ∆S for the reaction it describes. ∆H = +188.3 kJ. Which response describes the thermodynamic spontaneity of the reaction? 

1. The reaction is spontaneous only at relatively low temperatures. 

2. All responses are 

3. The reaction is spontaneous at all temperatures. 

4. The reaction is not spontaneous at any temperatures. 

5. The reaction is spontaneous only at relatively high temperatures

Which of the following statements concerning the second and third laws of thermodynamics is/are true? (I) When the change in entropy of the system is equal in magnitude and opposite in sign to the change in entropy of the surroundings, the change in entropy of the universe is zero. (II) The change in entropy of the universe can be rewritten as −∆Gsytem/T. (III) In a perfect, pure crystal at absolute zero the entropy of the system is zero. 

1. III only 

2. II, III 

3. I only 

4. I, III

5. II only 

6. I, II, III 

7. I, II