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8.1 Purity, formulations and chromatography

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Question 17
H

Four dyes were run on the same paper in the same solvent. Dye P had an Rf R_f\,Rf​ value of 0.28, dye Q 0.28, dye R 0.61 and dye S 0.83.

Which conclusion is correct?

[1]
A

Dyes P and Q may be the same compound, because their RfR_fRf​ values are equal in this solvent

B

Dyes P and Q must be the same compound, because equal RfR_fRf​ values show two dyes are identical

C

Dye S is a mixture of dyes, because it moved further up the paper than the other three dyes

D

Dye R is a pure compound, because its RfR_fRf​ value lies between the RfR_fRf​ values of the others

Markscheme

8.1 Purity, formulations and chromatography Questions

  1. GCSE
  2. /Chemistry
  3. /8.1 Purity, formulations and chromatography

40 exam-style questions on AQA GCSE Chemistry 8.1 Purity, formulations and chromatography, covering 8.1.1 Pure substances, 8.1.2 Formulations, and 8.1.3 Chromatography. Each one has a worked solution and a mark scheme showing where the marks go.

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