MHT CET Chemistry Question (2026) — Solution

Step-by-step solution

Urea-formaldehyde resin is a condensation polymer formed by the reaction between urea (NH_2-CO-NH_2) and formaldehyde (HCHO). The initial reaction involves the formation of methylol urea derivatives, which then undergo condensation with the elimination of water molecules to form a cross-linked polymer network. The repeating unit of the urea-formaldehyde polymer chain is derived from linking the nitrogen atoms of urea with the methylene (-CH_2-) group from formaldehyde. The repeating unit is [-NH-CO-NH-CH_2-]_n. Let us analyze the other options: Option (1) is polyacrylamide. Option (2) is polystyrene. Option (4) is nylon-6, which is polycaprolactam.