Concept:Bakelite (polyoxybenzylmethylenglycolanhydride) is a cross-linked phenolic resin prepared by the acid- or base-catalyzed condensation of phenol with formaldehyde.
Formula / Reaction:$$\text{C}_6\text{H}_5\text{OH} + \text{HCHO} \xrightarrow{\text{Acid or Base}} \text{Novolac / Resole} \xrightarrow{\Delta, \text{ Cross-link}} \text{Bakelite (3D Network)}$$
Solution:- Electrophilic aromatic substitution of formaldehyde at the ortho and para positions of phenol yields hydroxymethylphenols.
- Further thermal condensation forms methylene (\(-\text{CH}_2-\)) cross-links, producing a rigid, three-dimensional thermoset.
Why other options are incorrect:- Option A: Forms sodium phenoxide salt without polymer chain extension.
- Option B: Sulfonates the aromatic ring to produce phenolsulfonic acids.
- Option C: Esterifies phenol to yield phenyl acetate.
Quality & Fidelity Assurance:
Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.