Chromatography Flashcards
What are the phases of chromatography
a moving phase
a stationary phase
if a substance is attracted to the stationary phase what happens
it barely moves up the paper
what happens to substances attracted to the moving phase
they will move significantly up the paper
what happens during chromatography
substances are carried by moving phase some travel further then others, different components will travel different distances
what would happen if you used a pure substance for chromatography
only one spot would be seen moving
what is the point where the water stops called
the solvent front
how do you know how far each mixture has travelled
using a pencil mark in the centre of the spot
what is used to give a standardized answer for mixtures
a RETENTION FACTOR value
how do you work out an Rf value
distance travelled by substance/
distance travelled by solvent
What does the same Rf value indicate
the substances are likely to be the same even though they may have travelled different distances in different tests
