GCSE Chemistry Specification

OCR A J248

Section C2.1: Purity and separating mixtures

Are you studying this syllabus?

You can track your progress by adding it to your account.

Add syllabus

#C2.1a

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

#C2.1b

use melting point data to distinguish pure from impure substances

#C2.1c

calculate relative formula masses of species separately and in a balanced chemical equation

the definition of relative atomic mass, relative molecular mass and relative formula mass

#C2.1d

deduce the empirical formula of a compound from the relative numbers of atoms present or from a model or diagram and vice versa

#C2.1e

explain that many useful materials are formulations of mixtures

alloys

#C2.1f

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

knowledge of the techniques of filtration, crystallisation, simple distillation and fractional distillation

#C2.1g

describe the techniques of paper and thin layer chromatography

using aqueous and non-aqueous solvents and locating agents

#C2.1h

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

identification of the mobile and stationary phases

#C2.1i

interpret chromatograms, including measuring Rf values

the recall and the use of the formula

#C2.1j

suggest suitable purification techniques given information about the substances involved

#C2.1k

suggest chromatographic methods for distinguishing pure from impure substances

paper, thin layer (TLC) and gas chromatography