Preparation of Bakelite proceeds via reactions.

Solution

Chemistry ma’am · 4 steps

Formaldehyde attacks the phenol ring first, then the new CH₂OH groups link rings by losing water.

1. Starting materials. Bakelite is made from phenol and formaldehyde (HCHO), with an acid or base catalyst. The -OH group makes the phenol ring very electron-rich at the ortho and para positions.
2. Electrophilic substitution. The carbonyl carbon of formaldehyde is the electrophile. It attacks the ring at an ortho or para position, and the ring then loses H⁺ to become aromatic again. A ring H is replaced by -CH₂OH, so this is substitution, not addition.

   C₆H₅OH + HCHO → HO-C₆H₄-CH₂OH (o- and p-hydroxymethylphenol)

3. Dehydration. Each -CH₂OH group reacts with a ring H of another phenol and a molecule of H₂O is lost. This forms -CH₂⁻ bridges between rings: first the linear polymer Novolac, then, on further heating, the cross-linked network of Bakelite.
4. So. The two reaction types are electrophilic substitution on the phenol ring and dehydration to build the methylene bridges, which is option (a).

The idea to keep. Phenol rings get substituted, never added to, because they keep their aromaticity. In Bakelite, every -CH₂⁻ bridge is made when a -CH₂OH group and a ring H leave together as water.

Answer from the NTA final answer key. Solution by PrepWiser.