Chromatography
Theory Behind Chromatography:
Chromatography is the process of separating components of a mixture. The process
would begin when a mixture is placed onto the stationary phase and is then
separated when the mobile phase would pass through. These various components
of the mixture would move at different rates through the stationary phase based on
how polar or non-polar they are, this causes them to separate from one another.
(Ask a Science Staff, 2019).
Molecules polarity can affect the distance a sample would travel because it would
affect by its size. If they are a larger molecule the molecules would move up slowly,
whereas if they were smaller molecules the molecules would move up faster. How
far the spots can go can be impacted by the type of solvent has been used. Polar
molecules are more attracted to polar solvents and will travel further if there is a
polar solvent used rather than a nonpolar solvent. (BBC Bitesize,2019)
Paper Chromatography:
Equipment:
Grass
Sand
Pestle and mortar
Chromatography paper
Propanone
Matchstick
Pencil
Rule
Petroleum spirit
Test tube
Method:
1cm line was drawn above the bottom of the chromatography paper. A dot was
drawn in the middle of the line. In the mortar a small amount of grass was placed in
and a pinch of sand was dropped into it. A few drops of propanone were added to
grind up the grass with the pestle, the mortar was held to the side so the liquid had
extracted from the grass. A matchstick was used to place the liquid on the
chromatography paper on the dot. It was done for at least 10 times so the spot could
be more pigmented. We had waited in between applying spots and let it dry, so the
spot does not spread everywhere. The chromatography paper was placed in the test
tube using the crocodile clip on the lid, making sure it was straight and not touching
, the sides of the test tubes otherwise the spot would travel up fast. Once it has ran
up, it has been taken out and a solvent front has been drawn. Measure the height of
the spots and calculate the Rf values.
Risk Assessment:
Hazard Risk Precaution
Propanone (Cleapss, Can be flammable and Room should be
2019) irritant ventilated and if spilt on
skin keep had under
water for 10 mins.
Petroleum Spirit Flammable may cause Wear goggles, should be
(ReAgent, 2022) drowsiness. kept away from heat.
Glassware Can cut yourself or If dropped tell a teacher
someone else immediately.
Results:
Theory Behind Chromatography:
Chromatography is the process of separating components of a mixture. The process
would begin when a mixture is placed onto the stationary phase and is then
separated when the mobile phase would pass through. These various components
of the mixture would move at different rates through the stationary phase based on
how polar or non-polar they are, this causes them to separate from one another.
(Ask a Science Staff, 2019).
Molecules polarity can affect the distance a sample would travel because it would
affect by its size. If they are a larger molecule the molecules would move up slowly,
whereas if they were smaller molecules the molecules would move up faster. How
far the spots can go can be impacted by the type of solvent has been used. Polar
molecules are more attracted to polar solvents and will travel further if there is a
polar solvent used rather than a nonpolar solvent. (BBC Bitesize,2019)
Paper Chromatography:
Equipment:
Grass
Sand
Pestle and mortar
Chromatography paper
Propanone
Matchstick
Pencil
Rule
Petroleum spirit
Test tube
Method:
1cm line was drawn above the bottom of the chromatography paper. A dot was
drawn in the middle of the line. In the mortar a small amount of grass was placed in
and a pinch of sand was dropped into it. A few drops of propanone were added to
grind up the grass with the pestle, the mortar was held to the side so the liquid had
extracted from the grass. A matchstick was used to place the liquid on the
chromatography paper on the dot. It was done for at least 10 times so the spot could
be more pigmented. We had waited in between applying spots and let it dry, so the
spot does not spread everywhere. The chromatography paper was placed in the test
tube using the crocodile clip on the lid, making sure it was straight and not touching
, the sides of the test tubes otherwise the spot would travel up fast. Once it has ran
up, it has been taken out and a solvent front has been drawn. Measure the height of
the spots and calculate the Rf values.
Risk Assessment:
Hazard Risk Precaution
Propanone (Cleapss, Can be flammable and Room should be
2019) irritant ventilated and if spilt on
skin keep had under
water for 10 mins.
Petroleum Spirit Flammable may cause Wear goggles, should be
(ReAgent, 2022) drowsiness. kept away from heat.
Glassware Can cut yourself or If dropped tell a teacher
someone else immediately.
Results:
