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2 marksChromatographic Methods of Separation

CAPE Chemistry Unit 2 · 2012 · Paper 2 · Question 2(e)(ii)

Separation of dye components on a TLC plate.

Suggest TWO reasons for the difference in the Rf values of A and B.

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Other parts of this question

  1. 2(a)State ONE use of chromatography in criminal investigations.[1 mark]
  2. 2(b)Outline FOUR essential experimental steps in the separation of the components of a dye using thin-layer chromatography (TLC).[4 marks]
  3. 2(c)Define the terms 'stationary phase' and 'mobile phase' in relation to thin-layer chromatography (TLC).[2 marks]
  4. 2(d)Name TWO materials commonly used as the stationary phase in TLC.[2 marks]
  5. 2(e)(i)Calculate the Rf values of components A and B using the measurements provided in Figure 1.[2 marks]
  6. 2(e)(iii)State TWO factors, other than the distance travelled by the solvent, which influence the Rf value of a solute.[2 marks]

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