The correct option is **B. Polystyrene**. ### Detailed Explanation: 1. **Understanding Polymers**: - Polymers are large molecules made up of repeating structural units called monomers. The process of forming a polymer from monomers is known as polymerization. 2. **Styrene as a Monomer**: - Styrene is an organic compound that serves as a key monomer in the production of polystyrene. Its chemical structure is C8H8, which consists of a vinyl group (–CH=CH2) attached to a phenyl group (–C6H5). 3. **Polymerization of Styrene**: - The polymerization of styrene typically occurs through a process called free radical polymerization. In this process, free radicals initiate the reaction, leading to the formation of long chains of polystyrene. The reaction can be summarized as follows: \[ n \, \text{C}_8\text{H}_8 \rightarrow \text{(C}_8\text{H}_8\text{)}_n \] - Here, \( n \) represents the number of styrene monomers that join together to form the polymer. 4. **Properties and Uses of Polystyrene**: - Polystyrene is a versatile plastic that can be solid or foamed. It is lightweight, has good insulation properties, and is easy to mold, making it ideal for a wide range of applications, including: - Disposable cutlery and plates - Packaging materials (like foam peanuts and clamshell containers) - Insulation materials - Toys and household items ### Why Other Options Are Incorrect: - **A. Polyethylene**: - Polyethylene is derived from the polymerization of ethylene (C2H4), not styrene. It is widely used in plastic bags, bottles, and containers but does not share the same properties or applications as polystyrene. - **C. Polypropylene**: - Polypropylene is produced from the polymerization of propylene (C3H6). It is used in a variety of applications, including automotive parts, textiles, and packaging, but again, it is not derived from styrene. - **D. Polyvinyl Chloride (PVC)**: - PVC is made from the polymerization of vinyl chloride (C2H3Cl). It is commonly used in construction materials, plumbing, and electrical cable insulation. Like the others, it does not originate from styrene. ### Common Pitfalls: - Students may confuse the names of different polymers and their corresponding monomers. It is crucial to remember the specific monomer associated with each polymer. - Misunderstanding the polymerization process can lead to incorrect answers. Knowing the type of polymerization (addition vs. condensation) and the monomers involved is essential. ### Revision Summary: - **Polystyrene** is derived from the polymerization of **styrene**. - It is widely used in **household items** and **packaging materials**. - Other options (polyethylene, polypropylene, PVC) are derived from different monomers and have distinct applications. - Understanding the relationship between monomers and their corresponding polymers is key to mastering polymer chemistry.