Lowering in vapour pressure is a colligative property.

Explanation

To determine whether the statement "Lowering in vapor pressure is a colligative property" is true or false, we can analyze the concept of vapor pressure lowering and its relation to colligative properties step by step.

### Step-by-Step Solution:

1. **Understanding Vapor Pressure**:
- Vapor pressure is the pressure exerted by a vapor in equilibrium with its liquid or solid phase at a given temperature. For a pure solvent (let's denote it as A), the vapor pressure is denoted as \( P_{A0} \).

2. **Raoult's Law**:
- According to Raoult's Law, the vapor pressure of a solution (\( P \)) containing a solute (denote it as B) is given by:
\[ P = P_{A0} \cdot x_A \]
- Here, \( x_A \) is the mole fraction of the solvent A in the solution.

3. **Mole Fraction Relationship**:
- The mole fraction of the solute B can be expressed as:
\[ x_B = 1 - x_A \]
- Since the sum of the mole fractions of all components in a solution must equal 1, we have \( x_A + x_B = 1 \).

4. **Expression for Lowering of Vapor Pressure**:
- The lowering of vapor pressure (\( \Delta P \)) can be defined as:
\[ \Delta P = P_{A0} - P \]
- Substituting the expression from Raoult's Law, we get:
\[ \Delta P = P_{A0} - P_{A0} \cdot x_A = P_{A0} (1 - x_A) = P_{A0} \cdot x_B \]

5. **Colligative Properties**:
- Colligative properties are properties that depend on the number of solute particles in a solution, not on their identity. Examples include vapor pressure lowering, boiling point elevation, freezing point depression, and osmotic pressure.

6. **Conclusion**:
- Since the lowering of vapor pressure depends on the mole fraction of the solute (which is related to the number of solute particles), we can conclude that lowering of vapor pressure is indeed a colligative property.
- Therefore, the statement "Lowering in vapor pressure is a colligative property" is **true**.

### Final Answer:
The statement is **true**.