Select incorrect statements

Options

A. Osmotic pressure is a hypothetical pressure and is a colligative property.
B. Imbibition is adsorption without forming solution
C. At field capacity is 0.1 MPa
D. Velocity of ascent of xylem sap is 4mm/sec.

Explanation

To solve the question of selecting the incorrect statements, we will analyze each statement provided in the options.

### Step-by-Step Solution:

1. **Understanding Osmotic Pressure**:
- **Statement**: "Osmotic pressure is a hypothetical pressure and is a colligative property."
- **Analysis**: Osmotic pressure is indeed a hypothetical pressure that is defined as the pressure required to stop the flow of water into a solution through a semi-permeable membrane. It is also classified as a colligative property because it depends on the number of solute particles in a solution rather than their identity.
- **Conclusion**: This statement is **correct**.

2. **Understanding Imbibition**:
- **Statement**: "Imbibition is absorption without forming a solution."
- **Analysis**: Imbibition refers to the process where water is absorbed by hydrophilic (water-attracting) solid particles without the formation of a solution. This is a true statement as imbibition does not involve dissolving the absorbed water into the solid.
- **Conclusion**: This statement is **correct**.

3. **Understanding Field Capacity**:
- **Statement**: "At field capacity, the water potential is 0.1 MPa."
- **Analysis**: Field capacity refers to the amount of water soil can hold after excess water has drained away and the rate of downward movement has decreased. The water potential at field capacity is approximately 0.01 MPa, not 0.1 MPa.
- **Conclusion**: This statement is **incorrect**.

4. **Understanding Velocity of Ascent of Xylem Sap**:
- **Statement**: "The velocity of ascent of xylem sap is 4 mm per second."
- **Analysis**: The velocity of ascent of xylem sap can vary, but it is commonly accepted that it can be around 4 mm per second under certain conditions. Therefore, this statement is considered **correct**.

### Final Answer:
Based on the analysis, the incorrect statement is:
- **Option 3**: "At field capacity, the water potential is 0.1 MPa."