GCSE Chemistry OCR B J258

C5.1: How are chemicals separated and tested for purity?

#C5.1.1

explain that many useful materials are formulations of mixtures

#C5.1.2

explain what is meant by the purity of a substance, distinguishing between the scientific and everyday use of the term ‘pure’

#C5.1.3

use melting point data to distinguish pure from impure substances

#C5.1.4

recall that chromatography involves a stationary and a mobile phase and that separation depends on the distribution between the phases

#C5.1.5

interpret chromatograms, including calculating Rf values

#C5.1.6

suggest chromatographic methods for distinguishing pure from impure substances PAG4

Including the use of: a) paper chromatography b) aqueous and non-aqueous solvents c) locating agents

#C5.1.7

describe, explain and exemplify the processes of filtration, crystallisation, simple distillation, and fractional distillation PAG3, PAG7

#C5.1.8

suggest suitable purification techniques given information about the substances involved PAG3, PAG7

C4.5
What happens to products at the end of their useful life?
C5.2
How do chemists find the composition of unknown samples?