Thermodynamics Practice Questions
NEET · Chemistry · 1516 free MCQs with instant results and detailed explanations.
1516
Total
347
Easy
686
Medium
483
Hard
Start Practicing Thermodynamics
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Topics in Thermodynamics
Enthalpy
276
Entropy
259
First Law
255
Gibbs Energy
256
Hess's Law
214
Gibbs Free Energy
256
Sample Questions from Thermodynamics
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
What does the first law of thermodynamics state?
A.
Energy can be created or destroyed.
B.
Energy can be transformed but not created or destroyed.
C.
Entropy of an isolated system decreases over time.
D.
Heat flows from cold to hot spontaneously.
Show Answer & Explanation
Correct Answer: B
The first law of thermodynamics states that energy cannot be created or destroyed, only transformed from one form to another.
Q2
Easy
In a closed system, if a gas expands against a constant external pressure, which of the following represents the work done by the system?
A.
W = PĪV
B.
W = ĪV/P
C.
W = P Ć V
D.
W = V/P
Show Answer & Explanation
Correct Answer: A
The work done by the system during expansion against a constant pressure is given by W = PĪV, where ĪV is the change in volume.
Q3
Easy
Which of the following statements about internal energy (U) is correct?
A.
Internal energy is always zero.
B.
Internal energy depends only on temperature.
C.
Internal energy is a state function.
D.
Internal energy can be measured directly.
Show Answer & Explanation
Correct Answer: C
Internal energy (U) is a state function, meaning it depends only on the state of the system and not on how that state was achieved.
Q4
Medium
Which of the following statements best describes the First Law of Thermodynamics?
A.
Energy can be created and destroyed.
B.
Energy can be converted from one form to another, but cannot be created or destroyed.
C.
The total energy of an isolated system increases over time.
D.
Heat flows from a colder body to a hotter body spontaneously.
Show Answer & Explanation
Correct Answer: B
The First Law of Thermodynamics states that energy can neither be created nor destroyed, only transformed from one form to another.
Q5
Medium
If 500 J of work is done on a system and the internal energy of the system increases by 300 J, how much heat is released by the system?
A.
200 J
B.
300 J
C.
500 J
D.
800 J
Show Answer & Explanation
Correct Answer: A
According to the First Law, ĪU = Q + W. Rearranging gives Q = ĪU - W. Here, Q = 300 J - 500 J = -200 J (heat released).
Q6
Medium
Which process represents an isothermal expansion of an ideal gas?
A.
A gas expands and absorbs heat while maintaining constant temperature.
B.
A gas is compressed and releases heat at constant volume.
C.
A gas expands and cools down while doing work.
D.
A gas expands adiabatically without heat exchange.
Show Answer & Explanation
Correct Answer: A
Isothermal expansion occurs when a gas expands at constant temperature, absorbing heat to compensate for work done by the gas.
Q7
Medium
In a cyclic process, the work done by the system is 100 J and the heat absorbed from the surroundings is 250 J. What is the change in internal energy?
A.
100 J
B.
250 J
C.
350 J
D.
0 J
Show Answer & Explanation
Correct Answer: D
For a cyclic process, the change in internal energy (ĪU) is zero since the system returns to its initial state, regardless of work done or heat exchanged.
Q8
Hard
What is the change in internal energy when 100 J of heat is added to a system that does 60 J of work on the surroundings?
A.
40 J
B.
160 J
C.
100 J
D.
60 J
Show Answer & Explanation
Correct Answer: A
According to the first law of thermodynamics, ĪU = Q - W. Here, ĪU = 100 J - 60 J = 40 J.
Q9
Hard
In an isothermal process for an ideal gas, which of the following statements is true?
A.
Internal energy remains constant
B.
Temperature increases
C.
Heat is absorbed only
D.
Work done is zero
Show Answer & Explanation
Correct Answer: A
In an isothermal process, the temperature remains constant, thus the internal energy of an ideal gas, which depends only on temperature, also remains constant.
Q10
Hard
When 50 g of ice at 0Ā°C melts to water at 0Ā°C, how much heat is required? (Latent heat of fusion of ice = 334 J/g)
A.
16700 J
B.
1670 J
C.
334 J
D.
33400 J
Show Answer & Explanation
Correct Answer: A
Heat required for melting = mass Ć latent heat = 50 g Ć 334 J/g = 16700 J.
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Thermodynamics ā NEET Chemistry Practice Questions Online
This page contains 1516 practice MCQs for the chapter Thermodynamics in NEET Chemistry. The questions are organized by difficulty ā 347 easy, 686 medium, 483 hard ā so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit. This chapter covers 6 topics, giving you comprehensive coverage of the entire chapter.