C2 experimental techniques Flashcards
Describe Chromatography
A method of separating mixtures of soluble substances
Describe mixture
contains 2 or more substances not chemically combined
Describe Solvent
a substance that dissolves a solute
Describe stationary phase in chromatography
the paper in paper chromatography
Describe mobile phase in chromatography
the solvent in paper chromatography
Describe chromatogram
shows the results of separating the components of a mixture by chromatography
Describe impure substance
made of more than one thing and produces two or more spots on a chromatogram
Describe Rբ value
A way of measuring how far a spot has travelled on a chromatogram compared to the distance the solvent has travelled
Solvent front
the furthest point the solvent travels in paper chromatography
describe solute
a substance that is able to dissolve in a solvent
describe pencil line
doesn’t dissolve in the solvent so can be used as a baseline to make measurements in paper chromatography
What types of separation techniques are there? [4]
-Filtration
-Chromatography
-Crystallisation
-fractional/simple distillation
Describe Filtration [4]
-separates mixtures of insoluble solids and liquids
-by pouring mixture through filter paper
+solid trapped
+liquid run through
Describe Crystallisation [5]
-separates solutions into their contituent(different) parts
-solutes and solvents
-by heating the mixture so that the solvent evaporates
+crystal solutes
+collected solvent by condensing as it evaporates
Describe Fractional distillation
separates liquids with different boiling points
-mixture heated until the liquid with lowest boiling point boils and condenses
-increase temperatuer to collect the other fractions