Polymers with nitrogen in structure produce NOx on combustion

Steps:

• Identify chemical composition of each polymer.
• Check for nitrogen atoms in their repeating units.
• Recall that combustion of nitrogen-containing organics yields nitrogen oxides (NOx).
• Select the polymer with nitrogen.

Why A is correct:

• Nylon is a polyamide with -CONH- linkages containing nitrogen, which oxidizes to NOx during burning.

Why the others are wrong:

• B. Polythene is a hydrocarbon (polyethylene, -CH2-CH2-), lacks nitrogen.
• C. Starch is a polysaccharide (glucose units), contains only C, H, O.
• D. Terylene is a polyester (from terephthalic acid and ethylene glycol), no nitrogen.

Final answer: A