The free energy per mole of any substance in a chemical system is known as:

Options

A. osmotic potential
B. water potential
C. chemical potential
D. turgor pressure

Answer

To solve the question, "The free energy per mole of any substance in a chemical system is known as:", we will analyze the options provided and determine the correct answer step by step.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the term that describes the free energy per mole of any substance in a chemical system. This is a concept related to thermodynamics and chemical potential.

2. **Analyzing the Options**:
- **Option 1: Osmotic Potential**: This refers to the potential of water to move across a semipermeable membrane due to solute concentration. It is not the free energy per mole of a substance.
- **Option 2: Water Potential**: This is a measure of the potential energy in water, which includes osmotic potential and pressure potential. It does not specifically refer to the free energy per mole of a substance.
- **Option 3: Chemical Potential**: This term specifically refers to the change in free energy of a system when an additional amount of substance is added, making it the correct definition for the free energy per mole of any substance.
- **Option 4: Turgor Ratio**: This is related to the pressure within plant cells and does not describe free energy per mole.

3. **Identifying the Correct Answer**: Based on the analysis, the correct answer is **Chemical Potential** (Option 3).

4. **Conclusion**: The free energy per mole of any substance in a chemical system is known as **Chemical Potential**.

### Final Answer:
The correct answer is **Chemical Potential** (Option 3).