Second Law of Thermodynamics

Q. Considering entropy (S) as a thermodynamic parameter, the criterion for spontaneity of any process is ${\Delta }_{sys}S+{\Delta }_{surr}S>0$

1. True
2. False

Q. The total entropy change for a system and its surroundings increases, if the process is:

1. Reversible
2. Irreversible
3. Exothermic
4. Endothermic

Q.

Standard entropy of ${\mathrm{X}}_2,{\mathrm{Y}}_2\mathrm{and}{\mathrm{XY}}_3$ are $60,40\mathrm{and}50{\mathrm{JK}}^{-1}{\mathrm{mol}}^{-1}$, respectively. For the reaction, $\frac{1}{2}{\mathrm{X}}_2+\frac{3}{2}{\mathrm{Y}}_2\to {\mathrm{XY}}_3,\Delta \mathrm{H}=-30\mathrm{kJ}$ to be at equilibrium. What will be the temperature?

1. $500\mathrm{K}$

2. $750\mathrm{K}$

3. $1000\mathrm{K}$

4. $1250\mathrm{K}$

Q. During winters, moisture condenses in the form of dew and can be seen on plant leaves and grass. The entropy of the system in such cases decreases as liquids possess a lower disorder as compared to gases. With reference to the second law, which statement is correct, for the above process?

1. The randomness of the universe decreases
2. The randomness of the surrounding decreases
3. Increase in randomness of surroundings equals the decreases in randomness of system
4. The increase in randomness of the surrounding is greater as compared to the decrease in randomness of the system.

Q. For a reaction taking place in a container in equilibrium with its surroundings, the effect of temperature on its equilibrium constant K in terms of change in entropy is described by:

1. With increase in temperature, the value of K for exothermic reaction decreases because entropy change of the system is positive
2. With increase in temperature, the value of K for endothermic reaction increases because unfavourable change in entropy of the surroundings decreases
3. With increase in temperature, the value of K for endothermic reaction increases because the entropy change of the system is negative
4. With increase in temperature, the value of K for exothermic reaction decreases because favourable change in entropy of the surrounding decreases

Q. In each of the following question, an Assertion (A) is followed by a corresponding Reason (R). Use the following keys to choose the appropriate answer:

Assertion (A): There is a natural asymmetry between converting work to heat and converting heat to work.
Reason (R): No process is possible in which the sole result is the absorption of heat from a reservoir and its complete conversion into work.

1. If both (A) and (R) are correct, and (R) is the correct explanation for (A).
   
2. If the both (A) and (R) are correct, but (R) is not the correct explanation for (A).
   
3. If (A) is correct, but (R) is incorrect.
   
4. If (A) is incorrect, but (R) is correct.