Which among the following given properties is not a stable function

Options

A. internal energy
B. Enthalpy
C. Work
D. Entropy

Answer

To solve the question of which property is not a stable function, we need to understand the difference between state functions and path functions in thermodynamics.

### Step-by-Step Solution:

1. **Define State Functions and Path Functions**:
- State functions are properties that depend only on the current state of the system and not on how the system reached that state. Examples include internal energy, enthalpy, pressure, temperature, and volume.
- Path functions, on the other hand, depend on the specific path taken to reach a particular state. Work and heat are examples of path functions.

2. **Identify the Properties Given**:
- The question likely provides a list of properties. Without the specific properties listed, we will assume common thermodynamic properties such as internal energy, enthalpy, entropy, work, and heat.

3. **Analyze Each Property**:
- **Internal Energy**: A state function, as it depends only on the state of the system.
- **Enthalpy**: Also a state function, defined at a specific state of the system.
- **Entropy**: Another state function that depends on the state of the system.
- **Work**: A path function, as it depends on the process taken to do the work.
- **Heat**: Also a path function, as it depends on the way energy is transferred.

4. **Determine the Answer**:
- From the analysis, we find that work and heat are path functions, while internal energy, enthalpy, and entropy are state functions. Therefore, the property that is not a stable function (or state function) is **work**.

### Final Answer:
The property that is not a stable function is **work**.