explain what is meant by the purity of a substance, distinguishing between the scientific and everyday use of the term ‘pure’
explain what is meant by the purity of a substance, distinguishing between the scientific and everyday use of the term ‘pure’
use melting point data to distinguish pure from impure substances
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
deduce the empirical formula of a compound from the relative numbers of atoms present or from a model or diagram and vice versa
explain that many useful materials are formulations of mixtures
alloys
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
describe the techniques of paper and thin layer chromatography
using aqueous and non-aqueous solvents and locating agents
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
interpret chromatograms, including measuring Rf values
the recall and the use of the formula
suggest suitable purification techniques given information about the substances involved
suggest chromatographic methods for distinguishing pure from impure substances
paper, thin layer (TLC) and gas chromatography