Question

Which one of these is a monomer of Bakelite?
A. Vinyl acetate
B. Tetrafluoroethylene
C. Formaldehyde
D. Propylene

Answer 1

Hint: Polymers are made up of smaller units that are known as monomers. They bind to other monomers to form a repeating chain of molecules known as polymers. Similarly bakelite is a polymer which is made up of a monomer that has a pungent and suffocating odor.

Complete step by step answer:
- A monomer is a molecule that forms the basic unit of polymers. A monomer is a simple molecule that has two or more binding sites.
- The binding sites are used to form covalent linkages with other monomer molecules to form the macromolecule. This process is known as polymerization.
- All simple molecules do not behave as monomers, but only those molecules which have two or more building sites can act as a monomer.
- For example, ammonia, water, ethanol, etc are not monomers, but alkenes, vinyl chloride, adipic acid, phenol, formaldehyde, etc are monomers.
- Bakelite is a polymer that is made up of two monomers: phenol and formaldehyde. This is a thermosetting polymer.
- Bakelite is the common name for the polymer that is made from the polymerization of phenol and formaldehyde. Formaldehyde has a very pungent and a suffocating odor.
- In this, phenol is reacted with formaldehyde. The controlled reaction in the presence of acidic or basic medium results in the formation of ortho and para hydroxymethyl phenols and their derivatives.
- The process involved is shown below.


Therefore, formaldehyde and phenol are the monomers of Bakelite. Hence, the correct answer is option (C).

Note: Students tend to confuse between formaldehyde and acetaldehyde. Make sure you do not confuse between the two. Formaldehyde is $HCHO$ and acetaldehyde is $C{H}_{3}CHO$.