Question 1

Paper 2Medium6 marks

Brass is an alloy of copper and zinc. It is generally harder than pure copper. Figure 1 shows schematic representations of two brass samples and the structure of polymer P.

(a)Brass sample 1Brass sample 2CuCuZnCuCuCuCuZnZnCuCuCuCuZnCuCuCuZnCuZnCuCuZnCuZnCuCuZnCuZnCuCu(b)Polymer P[–CH2–CH2–]n
(a)

Use Figure 1(a) to explain why brass is classified as a mixture rather than a compound.

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(b)

Using Figure 1(a), explain how the structure of brass can account for its greater hardness than pure copper. Include the role of metallic bonding.

[2]
(c)

For polymer P in Figure 1(b), name the monomer and state the structural feature that identifies P as a polymer.

[2]

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