Chromatography
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What do chromatographic separations depend on?
the partition equilibrium between two phases, one stationary phase and the other mobile.
Describe paper chromatography.
the stationary phase is the water on the paper and the mobile phase is another solvent or solvent mixture.
Describe thin layer chromatography.
the stationary phase is a thin layer of aluminium oxide or silica gel on a glass plate or aluminium sheet and a solvent or solvent mixture is the mobile phase. Separation is much quicker than in paper chromatography
What kind of measurement do paper and thin-layer chromatography rely on?
measurements of Rf values for the identification of the components of a mixture
What is the retention time said to be for any given compound in a particular solvent mixture?
constant
What can Rf values be compared to?
published values
What is the equation to calculate Rf?
Rf = Distance moved by solute/ Distance moved by solvent