Purity, Formulations & Chromatography (AQA GCSE Chemistry): Flashcards
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Practise the cards
15 cards from this deck
Purpose of chromatography
Purpose of chromatography
Identify different substances in a mixture
Stationary phase in chromatography
Stationary phase in chromatography
The paper that stays still
Mobile phase in chromatography
Mobile phase in chromatography
The solvent that moves up the paper
Why use pencil not pen for start line
Why use pencil not pen for start line
Ink would interfere with results
Result for a pure substance
Result for a pure substance
Only one spot
Result for a mixture
Result for a mixture
Multiple spots
value formula
value formula
R_f = rac{ ext{distance of substance}}{ ext{distance of solvent}}
Range of values
Range of values
Always less than 1
Why substances separate in chromatography
Why substances separate in chromatography
Different attractions to paper and solvent
Critical rule for pencil line placement
Critical rule for pencil line placement
Must stay above the solvent level
What to mark when solvent stops rising
What to mark when solvent stops rising
The solvent front
Use of values
Use of values
To identify substances
What values depend on
What values depend on
Which solvent is used
Two phases in chromatography
Two phases in chromatography
Stationary (paper) and mobile (solvent)
What chromatography separates
What chromatography separates
Substances in a mixture