A teacher makes nylon. A solution of a diamine in water is poured gently on top of a solution of a diacid chloride in a solvent that does not mix with water. A film of nylon forms and is pulled out with tweezers.
Why does the nylon form only where the two layers meet?
The boundary is the hottest part of the beaker, so the reaction is fastest there.
The nylon is denser than the top solution, so it sinks to the boundary.
The solutions do not mix, so the two monomers only meet at the boundary.
Water acts as a catalyst for the reaction and is only found at the boundary.
63 exam-style questions on OCR GCSE Chemistry 6.2 Organic chemistry, covering 6.2.1 Crude oil and fractional distillation, 6.2.2 Cracking and dependence on hydrocarbons, 6.2.3 Functional groups and homologous series, 6.2.4 Reactions of alkanes, alkenes and alcohols, 6.2.5 Addition polymerisation and repeat units, 6.2.6 Naturally occurring polymers, 6.2.7 Chemical cells and fuel cells, and 6.2.8 Condensation polymerisation and how to make one. Each one has a worked solution and a mark scheme showing where the marks go.