Identify the incorrect statement

A. Bakelite and urea-formaldehyde resins are elastomers

B. Polyamides like nylon 6, nylon 6, 6 are examples of fibers.

C. Polystyrene, polyvinyl chloride and polythene are thermoplastic polymers.

D. Thermoplastic polymers have intermolecular force between elastomers and fibers.

Choose the most appropriate answer from the option given below:

A only

The correct answer is option 3. A only.

Let us break down each statement one by one to understand why statement A is incorrect and the others are correct.

A. Bakelite and urea-formaldehyde resins are elastomers.

The statement is incorrect. Bakelite and urea-formaldehyde resins are thermosetting plastics, not elastomers. Thermosetting plastics are polymers that undergo a chemical change when heated, causing them to harden permanently. Once set, they cannot be remolded or softened by heat.

Bakelite (a phenolic resin) is a hard, rigid polymer that is used for electrical insulators, handles, and other applications requiring high heat resistance. It cannot return to its original shape once deformed.

Urea-formaldehyde resins are also rigid and used in applications like adhesives, coatings, and molded objects, but they are not flexible or elastic.

Elastomers are polymers that can stretch significantly and return to their original shape when the deforming force is removed. Common examples include rubber and silicone, which have the ability to undergo large elastic deformations.

Therefore, Bakelite and urea-formaldehyde are not elastomers, making this statement incorrect.

B. Polyamides like nylon 6, nylon 6,6 are examples of fibers.

Polyamides are a class of polymers that contain amide linkages (-CONH-). Nylon 6 and nylon 6,6 are examples of polyamide fibers. Nylon 6 is made from a single monomer, caprolactam, and nylon 6,6 is made from two monomers, hexamethylenediamine and adipic acid. Both are synthetic fibers widely used in textiles, ropes, carpeting, and other applications requiring strength and durability.

These are fibers because of their molecular structure, which allows them to be drawn into long, flexible threads used in various textile applications. So, this statement is correct.

C. Polystyrene, polyvinyl chloride, and polythene are thermoplastic polymers.

Thermoplastic polymers are a class of polymers that soften when heated and can be reshaped. Upon cooling, they harden again, and this process is reversible. Polystyrene (PS), polyvinyl chloride (PVC), and polythene (PE) are examples of thermoplastic polymers.

Polystyrene is used in products like containers, insulation, and toys. Polyvinyl chloride (PVC) is commonly used in plumbing pipes, flooring, and electrical cables. Polyethylene (polythene) is used in a variety of everyday products like plastic bags, bottles, and containers.

These polymers are known for their ability to be melted and re-molded, which is characteristic of thermoplastics. Hence, this statement is correct.

D. Thermoplastic polymers have intermolecular force between elastomers and fibers.

Thermoplastic polymers have intermolecular forces that determine their properties. While this statement is somewhat broad, it's true in the sense that thermoplastics can exhibit a variety of intermolecular interactions, including those found in elastomers and fibers, depending on their structure and composition.

Elastomers are flexible and can stretch, as in the case of rubber, whereas fibers are typically long and strong polymers designed for strength, like nylon. Thermoplastics can exhibit both types of behavior depending on their molecular structure, which may resemble the intermolecular forces seen in elastomers or fibers.

Thus, this statement is correct.

Conclusion:

The incorrect statement is A, because Bakelite and urea-formaldehyde resins are thermosetting plastics, not elastomers. Elastomers are flexible, stretchable materials like rubber, which is not the case with Bakelite and urea-formaldehyde resins.

All other statements are correct because they describe the properties and uses of the respective polymers accurately.