Question

For the isothermal expansion of an ideal gas in a piston cylinder system, the net heat supplied during the process is equal to the net work. Which one of the following statements is correct for the given process?

• A. The process is possible.
• B. The process is not possible as it violates the second law of thermodynamics.
• C. The process is not possible as it violates the first law of thermodynamics.
• D. The process is possible, however, it violates the second law of thermodynamics.

Hint:

Recall that internal energy of an ideal gas depends only on temperature, and see what that means when temperature stays constant.

Answer 1

The Correct Option is A

Step 1: Apply the first law to the process.
The first law for a closed system reads \( Q = \Delta U + W \).
For an ideal gas, internal energy depends only on temperature, and the process here is isothermal, so \( \Delta U = 0 \).
That makes \( Q = W \) automatically true for any isothermal expansion of an ideal gas, exactly what the question states.

Step 2: Check the second law.
A quasi-static isothermal expansion exchanging heat with a reservoir at the same temperature as the gas is fully reversible, so no entropy is generated and no law is broken.
Nothing in the statement forces any irreversibility or any impossible heat flow.

Final Answer:
\( Q = W \) simply restates the first law for an isothermal ideal gas process, so the process is possible. \[ \boxed{\text{The process is possible}} \]