Thermodynamic parameter which is a state function and is also used to measure disorder of the system is

Options

A. Entropy
B. Fugacity
C. Viscosity
D. Periodicity

Answer

To answer the question regarding the thermodynamic parameter that is a state function and measures the disorder of a system, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding State Functions**:
- State functions are properties that depend only on the current state of a system, not on the path taken to reach that state. Examples include internal energy, enthalpy, and entropy.

**Hint**: Remember that state functions are determined by the initial and final states of a system.

2. **Identifying Path Functions**:
- In contrast, path functions depend on the specific path taken during a process. Work and heat are examples of path functions.

**Hint**: Path functions vary based on how the process is carried out, unlike state functions.

3. **Defining Disorder**:
- The term "disorder" in thermodynamics is often associated with the concept of entropy. Entropy quantifies the degree of randomness or disorder in a system.

**Hint**: Think about how the arrangement of particles in different states of matter (solid, liquid, gas) relates to disorder.

4. **Comparing Different States of Matter**:
- In solids, particles are closely packed and have low entropy (low disorder). In liquids, particles are more spread out, leading to higher entropy. In gases, particles are far apart and move freely, resulting in the highest entropy.

**Hint**: Consider how the arrangement of molecules changes from solid to liquid to gas and how this affects disorder.

5. **Conclusion**:
- Since entropy is a state function that measures the disorder of a system, it is the correct answer to the question posed.

**Final Answer**: The thermodynamic parameter that is a state function and measures the disorder of the system is **Entropy**.

### Summary:
- **State Function**: Depends on the state of the system (initial and final).
- **Path Function**: Depends on the process taken.
- **Disorder Measurement**: Entropy quantifies disorder in a system.