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In an adiabatic process, which of the following statements is true? (1) The molar heat capacity is zero (2) The molar heat capacity is infinite (3) The internal energy of the gas decreases as the temperature increases (4) Work done by the gas equals the increase in internal energy

1. The molar heat capacity is zero
2. The molar heat capacity is infinite
3. The internal energy of the gas decreases as the temperature increases
4. Work done by the gas equals the increase in internal energy

Correct answer: The molar heat capacity is zero

Solution

In an adiabatic process, there is no heat exchange with the surroundings, which means that any change in internal energy is solely due to work done on or by the system. Therefore, the molar heat capacity is effectively zero since no heat is added or removed.

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