The Student Room Group

Chromatography

Two dyes have the same rf values when tested using chromatography , does this mean they are the same dye or not ?
Original post by Syeda aleena
Two dyes have the same rf values when tested using chromatography , does this mean they are the same dye or not ?


Not necessarily. Whilst it's likely that they could be the same dye, it's still possible they could be different substances with very similar solubilities in the solvent used.

If you repeated the experiment, only changing the solvent, there could potentially be a difference in the Rf values, verifying the above statement.
Original post by Syeda aleena
Two dyes have the same rf values when tested using chromatography , does this mean they are the same dye or not ?


I think the way it is taught at A-level or GCSE you would probably say yes. Assuming the substance is completely pure ... each pure substance will have a unique rf value
Thank you : D
Original post by NoLimitAH
I think the way it is taught at A-level or GCSE you would probably say yes. Assuming the substance is completely pure ... each pure substance will have a unique rf value


Good point. Probably the safest answer to go with.

Quick Reply

Latest