Isothermal Process Characteristics Analysis

An isothermal process is a thermodynamic process where the temperature of the system remains constant throughout. Mathematically, this means:

$ \Delta T = 0 $

Thermodynamic Property Analysis

Let's analyze the given statements for an ideal gas undergoing an isothermal process:

• Statement (a): There is no change in enthalpy
  Enthalpy ($H$) for an ideal gas is a function of temperature only. The change in enthalpy ($\Delta H$) can be expressed as $\Delta H = n C_p \Delta T$, where $n$ is the number of moles and $C_p$ is the molar heat capacity at constant pressure.
  Since $\Delta T = 0$ in an isothermal process, it follows that: $ \Delta H = n C_p \times 0 = 0 $ Therefore, statement (a) is true.
• Statement (b): There is no change in internal energy
  For an ideal gas, internal energy ($U$) is also a function of temperature only. The change in internal energy ($\Delta U$) is given by $\Delta U = n C_v \Delta T$, where $C_v$ is the molar heat capacity at constant volume.
  As $\Delta T = 0$ in an isothermal process: $ \Delta U = n C_v \times 0 = 0 $ Thus, statement (b) is true.
• Statement (c): There is change in temperature
  The definition of an isothermal process explicitly states that the temperature remains constant ($\Delta T = 0$). Therefore, there is no change in temperature.
  This statement contradicts the definition of an isothermal process and is false.

Conclusion

Based on the analysis, statements (a) and (b) are true, while statement (c) is false.

The correct code representing the true statements is (a) and (b) only.