1. Extended tier only

To show that the polymer contains silver the following test was carried out. 

The polymer fibres were chopped into small pieces and warmed with nitric acid. The silver atoms were oxidised to silver(I) ions. The mixture was filtered. Aqueous sodium chloride was added to the filtrate and a white precipitate formed.

i) Why was the mixture filtered?

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ii) Explain why the change of silver atoms to silver ions is oxidation.

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iii) Give the name of the white precipitate.

[1]