Chemistry · THERMODYNAMICS

For an irreversible isothermal expansion of an ideal gas, which of the following conditions correctly describes \( \Delta U \) and \( \Delta S_{\text{total}} \)?

1. A
   \( \Delta U = 0 \) and \( \Delta S_{\text{total}} > 0 \)
2. B
   \( \Delta U = 0 \) and \( \Delta S_{\text{total}} = 0 \)
3. C
   \( \Delta U \neq 0 \) and \( \Delta S_{\text{total}} = 0 \)
4. D
   \( \Delta U > 0 \) and \( \Delta S_{\text{total}} < 0 \)