Thermodynamics Concepts Practice Test Quiz

1. What is thermodynamics?

• Thermodynamics is the examination of electromagnetic waves and their properties.
• Thermodynamics is the branch of physics and chemistry that studies the concepts of heat and temperature and the inter-conversion of heat and other forms of energy.
• Thermodynamics is the study of mechanical forces and their effects on matter.
• Thermodynamics is the analysis of the movement of celestial bodies in space.

2. What are the four laws of thermodynamics?

• The four laws of thermodynamics are the zeroth law, which defines temperature, the first law, which states energy conservation, the second law, which introduces entropy, and the third law, which describes absolute zero.
• The four laws of thermodynamics are energy conservation, heat transfer, work done, and entropic flow.
• The four laws of thermodynamics include potential energy, kinetic energy, thermal equilibrium, and energy displacement.
• The four laws of thermodynamics are heat storage, work efficiency, energy balance, and thermal dynamics.

3. Under what conditions is the heat evolved or absorbed equal to the internal energy change?

• The heat evolved or absorbed is equal to the internal energy change when work is done.
• The heat evolved or absorbed is equal to the internal energy change at constant pressure.
• The heat evolved or absorbed is equal to the internal energy change at constant volume.
• The heat evolved or absorbed is equal to the internal energy change during an isothermal process.

4. What is a cyclic process?

• A cyclic process is one that involves only heat transfer.
• A cyclic process is one that occurs at constant pressure.
• A cyclic process is one in which energy is completely wasted.
• A cyclic process is one in which the initial and final states are the same.

5. What are intensive and extensive properties of a system?

• Intensive properties include temperature and pressure, while extensive properties include color and density.
• Intensive properties depend on the size of the system, while extensive properties are independent of it.
• Intensive properties are related only to mass, whereas extensive properties are unrelated.
• Intensive properties include viscosity and refractive index, while extensive properties include mass, volume, and heat capacity.

6. What is the relationship between heat capacities at constant volume (Cv) and constant pressure (Cp)?

• Cv = Cp + R.
• Cp = Cv – R.
• Cv + Cp = 2R.
• Cp – Cv = R.

7. For a reaction with both ΔH and ΔS negative, under what conditions does the reaction occur spontaneously?

• The reaction occurs spontaneously at low temperatures.
• The reaction occurs spontaneously at high temperatures.
• The reaction occurs spontaneously under any conditions.
• The reaction does not occur spontaneously at low temperatures.

8. When heating a solution, which statement accurately characterizes the solution during a period of temperature increase?

• The solution is undergoing a phase change.
• The solution has reached absolute zero.
• The solution is in thermal equilibrium.
• The solution is cooling down rapidly.

9. What happens to internal energy in a cyclic process?

• The internal energy remains constant but is always negative in a cyclic process.
• The internal energy increases indefinitely in a cyclic process.
• The internal energy change is zero in a cyclic process.
• The internal energy decreases during a cyclic process.

10. What is the formula for Helmholtz free energy?

• F = U * TS.
• F = U + TS.
• F = U / TS.
• F = U – TS.

11. In which law of thermodynamics is entropy defined?

• The zeroth law of thermodynamics.
• The first law of thermodynamics.
• The third law of thermodynamics.
• The second law of thermodynamics.

12. What is the process where no heat transfer in or out of the system occurs?

• The process is an adiabatic process.
• The process is an isobaric process.
• The process is a cyclic process.
• The process is an isothermal process.

13. What is the formula for the ideal gas equation?

• PV = nRT.
• PV = nRT^2.
• P^2V = nRT.
• PV = nR^2T.

14. What is the difference between heat capacity and specific heat?

• Heat capacity is defined only for gases, while specific heat applies to solids only.
• Heat capacity refers to the total heat required to change a system`s temperature, while specific heat is the heat needed per unit mass.
• Heat capacity is a measure of energy in joules, while specific heat is expressed in calories.
• Heat capacity relates to mechanical work, while specific heat pertains only to chemical reactions.

15. What is the change in internal energy of a gas when it is heated from 300 K to 500 K and then cooled back to 300 K?

• The change in internal energy is zero because the initial and final states are the same in a cyclic process.
• The change in internal energy is equal to the temperature difference multiplied by specific heat.
• The change in internal energy is equal to the work done on the gas.
• The change in internal energy is equal to the heat added during heating.

16. What is the effect of temperature on entropy?

• The entropy of a system increases as the temperature increases.
• The entropy of a system remains constant as the temperature increases.
• The entropy of a system decreases as the temperature increases.
• The entropy of a system fluctuates randomly with temperature changes.

17. What is the measurement of energy in a thermodynamic system?

• Mass
• Enthalpy
• Velocity
• Pressure

18. What is the formula for internal energy?

• U = CvT.
• U = PV.
• U = ∫TdS – PdV + ∑iμidNi.
• U = mgh.

19. What is the application of thermodynamics in everyday life?

• Thermodynamics has no impact on daily cooking or food preservation techniques.
• Thermodynamics is used only in high-temperature reactions and chemical processes.
• Thermodynamics applies exclusively to laboratory experiments and not in real-world applications.
• Thermodynamics is applied in refrigerators, gas compressors, power plants, and other devices that involve heat transfer and energy conversion.

20. What is thermal efficiency?

• Thermal efficiency is the maximum temperature a system can reach.
• Thermal efficiency is the total heat absorbed by a system during a process.
• Thermal efficiency is the sum of all energy inputs in a thermodynamic cycle.
• Thermal efficiency is the ratio of the work output to the heat input in a thermodynamic cycle.

21. What is the direction of heat transfer?

• Heat flows from a low-temperature system to a high-temperature system.
• Heat flows from a high-temperature system to a low-temperature system.
• Heat flows only when a system is at equilibrium.
• Heat flows equally in all directions without a temperature gradient.

22. Who proved that heat is a type of energy?

• Newton
• Joule
• Einstein
• Galileo

23. What happens to entropy in an isolated system?

• The entropy of an isolated system always increases and remains constant only when the process is reversible.
• The entropy of an isolated system remains the same indefinitely.
• The entropy of an isolated system fluctuates randomly without a trend.
• The entropy of an isolated system decreases over time.

24. What is the effect on entropy when heat flows reversibly from a system to the surroundings?

• The entropy of the surroundings increases, and the system loses entropy.
• The entropy of the system and surroundings both decrease.
• The entropy remains constant in both the system and surroundings.
• The entropy of the system increases, and the surroundings lose entropy.

25. How does entropy increase in a closed system?

• Entropy increases due to dissipative effects or internal irreversibilities and by heat interaction with entropy transfer.
• Entropy decreases due to external energy input and ordered phase transitions.
• Entropy only increases when a system expands against external pressure.
• Entropy remains constant as heat is transferred within an isolated system.

26. What is the thermal efficiency of a car using 25 hp for a one-hour round trip?

• 25%
• 35%
• 60%
• 50%

27. What is the relationship between Gibbs free energy and the spontaneity of a reaction?

• The spontaneity of a reaction is determined by T > ΔS.
• The spontaneity of a reaction is determined by ΔG = ΔH + TΔS.
• The spontaneity of a reaction is determined by ΔG < 0.
• The spontaneity of a reaction is determined by ΔH > 0.

28. What is the formula for Gibbs free energy?

• G = H + TS.
• G = TS – H.
• G = H * T / S.
• G = H – TS.

29. What is the significance of the third law of thermodynamics?

• The third law of thermodynamics outlines the relationship between pressure and volume in gases.
• The third law of thermodynamics describes absolute zero and the behavior of entropy as it approaches absolute zero.
• The third law of thermodynamics states that energy cannot be created or destroyed in a process.
• The third law of thermodynamics explains how heat transfers between systems at different temperatures.

30. What is the difference between an open, closed, and isolated system?

• An open system allows energy transfer only, a closed system allows mass transfer only, and an isolated system allows both energy and mass transfer.
• An open system allows energy transfer only, a closed system allows energy and mass transfer, and an isolated system allows only energy transfer.
• An open system allows neither energy nor mass transfer, a closed system allows both, and an isolated system allows energy transfer only.
• An open system allows energy and mass transfer, a closed system allows energy transfer but not mass, and an isolated system allows neither energy nor mass transfer.