First law of thermodynamics and internal energy - One Line Questions

1. In a system where 200 J of heat is removed and 50 J of work is done on the system, what is the change in internal energy? — -250 J
2. What is the value of Q when ΔU = -100 J and W = 30 J (work done by the system)? — -70 J
3. When a system expands against a constant external pressure, the work done BY the system is given by: — PΔV
4. If a system's internal energy increases by 200 J and it does 100 J of work, how much heat was supplied? — 300 J
5. What is the change in internal energy when 100 J of heat is supplied to a system, and 100 J of work is done by the system? — 0 J
6. If a system releases 200 J of heat and its internal energy decreases by 100 J, how much work is done ON the system? — 100 J
7. For a diatomic ideal gas, the internal energy per mole is U = (5/2)RT. If 1 mole of this gas undergoes an isobaric expansion where heat added is 250 J, what is the change in internal energy? — 200 J
8. For a polyatomic ideal gas, the internal energy per mole is U = (f/2)RT, where 'f' is the number of degrees of freedom. If f=6, what is the change in internal energy when 2 moles are heated by 50 K? — 600 R
9. For a monatomic ideal gas, the internal energy per mole is given by U = (3/2)RT. What is the change in internal energy when 2 moles of this gas are heated from 300 K to 400 K? — 3000 R
10. Consider a system where 50 J of work is done ON the system, and 100 J of heat is supplied. What is the change in internal energy? — 150 J
11. If a system undergoes a process where ΔU = 100 J and Q = 50 J, what is the work done by the system? — -50 J
12. What is the value of Q for a system that performs 100 J of work and experiences a decrease in internal energy of 50 J? — 50 J
13. If a system absorbs 100 J of heat and performs 40 J of work, what is the change in its internal energy? — 60 J
14. If Q = 50 J and W = 20 J (work done by the system), what is ΔU? — 30 J
15. The internal energy of a system is 500 J. If 300 J of heat is added and 100 J of work is done by the system, what is the final internal energy? — 700 J
16. If a system does 50 J of work and absorbs 30 J of heat, what is the change in internal energy? — -20 J
17. For a system at constant temperature undergoing a process, the change in internal energy is: — Zero for an ideal gas
18. In a cyclic process, the system returns to its initial state. What is the change in internal energy for a cyclic process? — Always zero
19. The First Law of Thermodynamics is applicable to: — All natural phenomena involving energy
20. Which of the following statements best describes the First Law of Thermodynamics? — Energy cannot be created or destroyed, only converted from one form to another.
21. Consider an isolated system. According to the First Law of Thermodynamics, what is the change in internal energy if no heat is exchanged with the surroundings? — Equal to the work done
22. Which of the following is NOT a form of energy transfer that affects internal energy? — Mass transfer
23. Which of the following is a state function in thermodynamics? — Internal Energy (U)
24. What does 'ΔU' symbolize in the equation ΔU = Q - W, where ΔU is the change in internal energy, Q is heat added, and W is work done by the system? — Change in internal energy
25. If a system does work on the surroundings (W > 0) and absorbs heat (Q > 0), its internal energy will: — Cannot be determined without more information
26. If a system is compressed adiabatically, what happens to its internal energy? — Increases
27. If work is done ON the system (W is negative in the formula ΔU = Q - W), and heat is released by the system (Q is negative), what happens to the internal energy? — Decreases
28. When a gas expands, it does work on the surroundings. If this expansion occurs adiabatically, what happens to the internal energy of the gas? — Decreases
29. What is the internal energy of an ideal gas at absolute zero temperature (0 K)? — Minimum possible value
30. Which of the following quantities is NOT a measure of energy? — Pressure
31. In adiabatic processes, there is no heat exchange with the surroundings. What is the consequence for the internal energy according to the First Law? — Internal energy changes solely due to work done.
32. Which type of process involves no change in internal energy for an ideal gas? — Isothermal
33. What is the nature of internal energy for an ideal gas? — It depends only on temperature.
34. In an isobaric process, heat is added to a system, and the system expands. What happens to the internal energy? — It increases.
35. In an isothermal process for an ideal gas, the temperature remains constant. What can be said about the change in internal energy? — It remains constant.
36. If heat is supplied to a system and its internal energy decreases, what must have happened to the work done? — It must be positive (work done by the system).
37. Which statement is FALSE regarding the First Law of Thermodynamics? — It dictates the direction of heat flow.
38. The First Law of Thermodynamics is essentially a statement of the conservation of: — Energy
39. What does the term 'internal energy' in thermodynamics encompass? — The sum of kinetic and potential energies of molecules within the system.
40. The First Law of Thermodynamics prohibits: — Perpetual motion machines of the first kind (machines that produce work without consuming energy).
41. If a gas is heated at constant volume, what is the work done by the gas? — Zero
42. What is the work done by a system during an isochoric process (constant volume)? — Zero
43. The internal energy of a substance is dependent on: — Temperature and Phase
44. For an ideal gas, internal energy is a function of: — Temperature only
45. For a process where ΔU = 0, what is the relationship between heat and work? — Q = W
46. The internal energy of a real gas differs from that of an ideal gas primarily because: — Real gases have intermolecular forces.
47. For an ideal gas, the change in internal energy depends solely on the change in: — Temperature
48. In the context of the First Law of Thermodynamics, what does the term 'Q' represent? — Heat supplied to the system
49. Which statement is true about work done in thermodynamic processes? — Work is path-dependent.
50. In the equation ΔU = Q - W, if the process is such that W = Q, then: — ΔU = 0
All One Line Questions
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