Chromotography

Question 1

What is it used for?

Answer 1

separate mixtures of coloured compounds

Question 2

How to calculate Rf value?

Answer 2

Rf = distance moved by the compound ÷ distance moved by the solvent(water)

Question 3

name 2 phases of chtgy

Answer 3

mobile -liquid(water usually)

stationary-solid(usually paper)

Question 4

Setting up chromatography

Answer 4

draw pencil line near bottom of paper (1cm above)
put spot of mixture on line
put some solvent into beaker -dip bottom of paper into
solvent not the spot tho
put watch glasss on top beaker prevent solvent evap
solvent start to move up paper .Chemicals in mixture dissolve in solvent they will move up paper too

see different chemicals in the sample separate out forming spots at diff places on paper

Question 5

The amount of time the molecules spend in each phase depend on how ________ they are in the solvent
and how _______they are to the stationary phase

Answer 5

soluble

attracted

Question 6

molecules with higher solubility in solvent (which r less attracted to paper ) spend more time in_______phase-so they ‘ll be
carried up ______the paper

Answer 6

mobile

further

Question 7

why is a pencil mark used?

Answer 7

insoluble won t move with solvent as ink might