The addition polymer poly(butene) has the displayed structural formula: CH₃ CH₃ | | H–C – C–H | | H H Poly(butene) is produced from the monomer butene - AQA - GCSE Chemistry - Question 1 - 2022 - Paper 2

Poly(butene) insulation must be removed because it can contaminate the copper during the melting process. Contamination can affect the quality of the recycled copper, making it less suitable for reuse in manufacturing.

Scrap copper wire is first sorted and cleaned to remove any insulation or impurities. It is then melted down in a furnace. Once melted, the copper is cast into molds to form the desired shapes for new water pipes. Finally, the copper pipes are cooled and tested for quality before distribution.

1. Recycling scrap copper requires significantly less energy compared to mining and processing copper from ores, reducing carbon emissions.
2. It conserves natural resources by reducing the need for mining, which can lead to habitat destruction and pollution.

The solution added is sodium hydroxide (NaOH).

The result of the test is a blue color, indicating the presence of copper(II) ions.

A barium chloride test can be performed. By adding dilute hydrochloric acid followed by barium chloride solution to the copper sulfate solution, a white precipitate of barium sulfate will form if sulfate ions are present.

The result of the test is the formation of a white precipitate, confirming the presence of sulfate ions.