Question

What are the monomers of Bakelite?

• A. Ethylene and Styrene
• B. Phenol and Formaldehyde
• C. Vinyl chloride and Ethylene
• D. Urea and Formaldehyde

Hint:

Important polymers and their monomers: Bakelite → Phenol + Formaldehyde Nylon-6,6 → Hexamethylenediamine + Adipic acid PVC → Vinyl chloride

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks for the primary chemical building blocks (monomers) used to synthesize Bakelite, a well-known thermosetting polymer.
Step 2: Key Formula or Approach:
Bakelite is a cross-linked polymer formed via a condensation reaction. Knowing the commercial name for "phenol-formaldehyde resin" directly answers the question.
Step 3: Detailed Explanation:
1. Bakelite is synthesized by the reaction of Phenol with Formaldehyde in the presence of either an acid or a base catalyst.
2. The initial reaction produces linear chains (Novolac).
3. Further heating with more formaldehyde leads to extensive cross-linking, resulting in the hard, infusible solid known as Bakelite.
4. Formaldehyde acts as the bridging unit (\(-CH_2-\) groups) between the phenol rings.
Step 4: Final Answer:
The monomers of Bakelite are Phenol and Formaldehyde (B).