Common monomer present in Melamine Formaldehyde polymer and Bakelite is
(A) Formaldehyde
(B) Phenol
(C) Melamine
(D) Ethylene Glycol

Hint: It is an aldehydic simple chemical compound made of hydrogen, oxygen and carbon. It is a colourless compound which has a pungent smell.

Complete step by step solution:
Now, let us know about the formation of Melamine Formaldehyde
-Melamine (1, 3, 5-triamino-2, 4, 6-triazine) formaldehyde.
-Melamine formaldehyde (MF) polymers are primarily made up of melamine and formaldehyde with formaldehyde.

-Monomers of Melamine Formaldehyde are Melamine and Formaldehyde.
Additional Information:
-Melamine formaldehyde is a hard, durable, and versatile thermosetting amyloplast with good fire and heat resistance.
-It is an amino resin and has various material advantages, such as transparency, better hardness, thermal stability, excellent boil resistance, scratch resistance, abrasion resistance, flame retardant, moisture resistance and surface smoothness, which lead MF to large industrial applications.
Now, we learn the preparation of Bakelite
-Bakelite ${({C_6} - {H_6} - O.C - {H_2} - O)_x}$
-Bakelite is produced through condensation reaction between phenol and formaldehyde in the presence of either basic or acidic catalyst.

-Monomers of Bakelite are Phenol and Formaldehyde.

Hence, the common monomer of Melamine Formaldehyde and Bakelite is Formaldehyde. Therefore, Option (A)is correct.

Additional information:
-It is a thermo-setting and cross-linked polymer.
-Bakelite is a non-conductive and heat resistant material that makes it ideal for electrical insulators. It’s rigid, hard, scratch-resistant, infusible, water-resistant, insoluble solid and a good insulator.
-It was used for its non-conductive and heat-resistant properties in electrical insulators, and also in radios and telephones.
By learning the preparation of Bakelite and Melamine Formaldehyde we got to know that the monomers used for the preparation of Melamine are Melamine and Formaldehyde and the monomers used for the preparation of Bakelite are Formaldehyde and Phenol.

Note: 1. Phenol and Formaldehyde are required for the formation of Bakelite whereas Melamine and Formaldehyde are required for Melamine Formaldehyde polymer.
2. Do not get confused by the occurrence of Phenol and Melamine as the two are also monomers.