The solution of rubber in benzene is an example of

Options

A. Multimolecular colloid
B. Macromolecular colloid
C. Associated colloid
D. Lyophobic colloid

Answer

To determine the type of colloid formed by the solution of rubber in benzene, we can analyze the properties of rubber and the nature of the solution:

### Step-by-Step Solution:

1. **Identify the Nature of Rubber**:
- Rubber is a polymer, which means it consists of large molecules made up of repeating structural units. The primary monomer of rubber is isoprene.

2. **Understand the Size of Rubber Molecules**:
- The size of rubber molecules is significantly larger than that of small molecules. Polymers like rubber have molecular weights that can be very high, often in the thousands or millions.

3. **Determine the Type of Colloid**:
- Colloids can be classified into different categories based on the size of the dispersed phase:
- **Multi-molecular Colloids**: These consist of aggregates of small molecules (size range: 1 nm to 1000 nm).
- **Macromolecular Colloids**: These consist of large molecules (size range: 1 nm to 1000 nm) that are themselves colloidal in size.
- **Associated Colloids**: These are formed by the aggregation of smaller molecules into larger structures, typically in specific conditions.
- **Lyophobic Colloids**: These do not mix well with the solvent and are not stable in the presence of a solvent.

4. **Analyze the Solvent (Benzene)**:
- Benzene is a suitable solvent for rubber, allowing the large rubber molecules to remain dispersed in the solution.

5. **Conclusion**:
- Since rubber is a large molecule and forms a stable solution in benzene, the solution of rubber in benzene is classified as a **macromolecular colloid**.

### Final Answer:
The solution of rubber in benzene is an example of **macromolecular colloid**.