Which of the following statements is false ?

Options

A. Units of atmospheric pressure and osmotic pressure are the same
B. In reverse osmosis, solvent molecules move through a semipermeable membrane from a region of lower concentration of solute to a region of higher concentration
C. The value of molal depression constant depends on nature of solvent
D. Relative lowering of vapour pressure, is a dimensionless quantity.

Answer

To determine which of the following statements is false, we will analyze the statements related to atmospheric pressure, osmotic pressure, osmosis, and reverse osmosis.

### Step-by-Step Solution:

1. **Understanding Atmospheric Pressure and Osmotic Pressure:**
- Both atmospheric pressure and osmotic pressure are measured in units of pressure. Common units include atmospheres (ATM), pascals (Pa), and bars.
- Therefore, the statement that the units of atmospheric pressure and osmotic pressure are the same is **true**.

2. **Understanding Osmosis:**
- Osmosis is defined as the movement of solvent particles through a semi-permeable membrane from a region of lower solute concentration (C2) to a region of higher solute concentration (C1).
- This statement is also **true**.

3. **Understanding Reverse Osmosis:**
- Reverse osmosis is the process where solvent particles move from a region of higher solute concentration to a region of lower solute concentration, which is the opposite of osmosis.
- This statement is **true**.

4. **Molar Depression Constant:**
- The molar depression constant is a property that depends on the nature of the solvent. This means that different solvents will have different molar depression constants.
- This statement is **true**.

5. **Identifying the False Statement:**
- Since all the statements regarding atmospheric pressure, osmotic pressure, osmosis, reverse osmosis, and the molar depression constant are true, we need to identify if any of the statements provided in the question were misrepresented or misunderstood.
- If the question provided specific statements, we would analyze them one by one to find the false one. However, based on the information provided in the transcript, it appears that the initial claim about the units being the same is the only one that could be misinterpreted if not presented correctly.

### Conclusion:
The false statement among the options is likely the one that incorrectly states the relationship between atmospheric pressure and osmotic pressure or misrepresents the principles of osmosis or reverse osmosis.