1. Which of the following is a state function?
Answer:
Explanation:
State functions depend only on the initial and final states, not on the path. Internal Energy is a state function.
2. The entropy of an isolated system:
Answer:
Explanation:
According to the second law of thermodynamics, the entropy of an isolated system always increases.
3. Which of the following processes is isothermal?
Answer:
Explanation:
In free expansion, there is no exchange of heat or work, thus the temperature remains constant.
4. The unit of Gibbs free energy (G) is:
Answer:
Explanation:
Gibbs free energy has the unit of energy per mole, which is J/mol.
5. For a spontaneous process:
Answer:
Explanation:
A process is spontaneous if the Gibbs free energy change, ΔG, is negative.
6. The third law of thermodynamics states:
Answer:
Explanation:
The third law of thermodynamics defines the zero point of entropy.
7. Which of the following statements is true for an endothermic reaction?
Answer:
Explanation:
An endothermic reaction absorbs heat, resulting in a positive ΔH.
8. The change in internal energy for an isochoric process is equal to:
Answer:
Explanation:
In an isochoric process, volume is constant, so work (w) is zero. Thus, ΔU = q.
9. For an ideal gas, which of the following is true?
Answer:
Explanation:
For an ideal gas, change in internal energy is only dependent on temperature change.
10. Entropy is a measure of:
Answer:
Explanation:
Entropy measures the degree of randomness or disorder in a system.
11. Which of the following processes is reversible?
Answer:
Explanation:
Reversible processes are carried out infinitely slowly to maintain equilibrium.
12. In an adiabatic process:
Answer:
Explanation:
In an adiabatic process, there is no heat exchange with the surroundings.
13. Which law states that energy can neither be created nor destroyed?
Answer:
Explanation:
The First Law of Thermodynamics is the law of conservation of energy.
14. A process that is not spontaneous in one direction will be ________ in the reverse direction.
Answer:
Explanation:
If a process is non-spontaneous in one direction, its reverse process is spontaneous.
15. Which of the following quantities is extensive?
Answer:
Explanation:
Extensive properties depend on the amount of matter in the system, like volume.
16. Standard enthalpy changes are measured at:
Answer:
Explanation:
Standard conditions are 1 atm pressure and 25°C (298K) temperature.
17. An exothermic reaction has:
Answer:
Explanation:
An exothermic reaction releases heat, resulting in a negative ΔH.
18. For a given gas, which is always true?
Answer:
Explanation:
This is the relationship between enthalpy and internal energy for a gas.
19. The spontaneity of a process can be predicted using:
Answer:
Explanation:
Gibbs free energy (ΔG) is the primary criteria for spontaneity.
20. In an isothermal reversible expansion of an ideal gas:
Answer:
Explanation:
For isothermal expansion of an ideal gas, ΔU = 0, hence q = w.