#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