Question 1: Define condensation polymerisation and explain its significance in producing polymers.

Answer: Condensation polymerisation is a chemical process where monomers join together releasing small molecules such as water or methanol, forming polymers; it is significant because it produces many important polymers like nylon and polyester.

Question 1: Describe the key functional groups involved in the formation of nylon 6,6 during condensation polymerisation.

Answer: The key functional groups are amine (-NH₂) groups and carboxylic acid (-COOH) groups, which react to form amide linkages (-CONH-) while releasing water.

Question 1: Calculate the molar mass of the repeat unit in nylon 6,6, given that the monomers are hexamethylenediamine (C₆H₁₆N₂) and adipic acid (C₆H₁₀O₄).

Answer: Molar mass of repeat unit = (C₆H₁₆N₂ + C₆H₁₀O₄) - 2 H₂O = (6×12.01 + 16×1.008 + 2×14.01) + (6×12.01 + 10×1.008 + 4×16.00) - 2×(2×1.008 + 16.00) = (72.06 + 16.13 + 28.02) + (72.06 + 10.08 + 64.00) - 2×(2.016 + 16.00) = 116.21 + 146.14 - 2×18.02 = 262.35 - 36.04 = 226.31 g/mol

Question 1: Outline a basic experimental procedure to synthesise nylon 6,6 in a school laboratory, including safety precautions.

Answer: To synthesise nylon 6,6, mix hexamethylenediamine and adipic acid in a suitable solvent in a well-ventilated area, wear safety goggles and gloves, heat gently under controlled conditions to promote polymer formation while avoiding spills or inhalation of fumes. Ensure proper disposal of waste and monitor temperature closely.

Question 1: A sample of polyester fibre was analysed and found to contain 62.5% carbon, 5.0% hydrogen, and 32.5% oxygen by mass. Calculate the empirical formula of the repeat unit.

Answer: Assuming 100 g sample: C: 62.5 g / 12.01 g/mol ≈ 5.20 mol H: 5.0 g / 1.008 g/mol ≈ 4.96 mol O: 32.5 g / 16.00 g/mol ≈ 2.03 mol Divide each by smallest (2.03 mol): C: 5.20/2.03 ≈ 2.56 H: 4.96/2.03 ≈ 2.45 O: 2.03/2.03 ≈ 1 Approximate to whole numbers: C₃, H₂₅, O Empirical formula: C₃H₂₅O

Question 1: Explain how condensation polymers are utilised in the manufacturing of fibres and plastics, highlighting their advantages.

Answer: Condensation polymers like nylon and polyester are used in fibres and plastics due to their strength, durability, and resistance to chemicals. They are advantageous because they can be produced efficiently through polymerisation reactions that release small molecules, allowing for versatile applications in textiles, packaging, and engineering materials.

Question 1: Summarise the main features of condensation polymerisation and its importance in modern chemistry.

Answer: Condensation polymerisation involves monomers joining with the release of small molecules like water, forming polymers. It is important because it produces many high-performance and biodegradable polymers used in everyday life, industry, and technology.