paper / TLC Flashcards
1
Q
what is the stationery phase?
A
- chromatography paper
- sample placed onto it
- doesn’t move
2
Q
what is the mobile phase?
A
- solvent
- moves over stationery phase
3
Q
what is meant by adsorption?
A
reactant molecule sticks to surface of catalysts
4
Q
what does it mean if a sample moves slower?
A
well adsorbed
5
Q
what does it mean if a sample moves faster?
A
less adsorbed
6
Q
what is the Rf value equation?
A
distance moved by spot / distance moved by solvent
7
Q
define Rf value
A
under similar conditions, a component should always travel at the same speed
8
Q
what is a limitation of paper chromatography?
A
only works with coloured components
9
Q
what is the stationery phase in TLC?
A
silica mounted to glass plate
10
Q
what is the mobile phase in TLC?
A
suitable organic solvent
11
Q
what are the limitations of TLC?
A
- components overlap so cannot see them all easily
- no Rf value
- can’t identify where one component has moved to
