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can someone provide a sample answer to this q part b (1 Viewer)

jimmysmith560

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In developing a response to this part of the question, you should consider the following scaffold:

1651842716247.png

I hope this helps! :D
 

someth1ng

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In developing a response to this part of the question, you should consider the following scaffold:
I kinda hate how it's an "evaluate" question. In reality, it should just be: "the experiment has no repetitions, so it is not reliable".

Anyway, a couple of points to consider:
  • Probably better to filter with a Buchner funnel with filter paper (sintered glass is honestly pretty bad since a lot of crap gets stuck in the glass).
  • Fertiliser is dissolved in an undefined water volume. If they use an absurdly large volume in one test (e.g. 5 L), then solubility in the large volume can become an issue. They should be dissolving in a set volume of water (where it is fully dissolved). Water should also be deionised.
  • Barium chloride should be in great excess to ensure complete precipitation. They've only included 2.6 g of BaCl2 and there is 1.0 g of fertiliser, which isn't clearly defined either.
  • Other barium salts could be precipitating (e.g. barium phosphate), considering other anions are used for fertiliser too.
 

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