3.5 Chromatography Flashcards
(16 cards)
What is chromatography
A technique which can be used to separate the components in a mixtures
What are the 2 factors that affect separation in chromatography
Size and Polarity
Why do larger molecules more slower on chromatography paper
because they are heavier
Why do smaller molecules move slower on chromatography paper
They are more mobile
What does polarity in chromatography depend on
The solvent being used
Why does polarity in chromatography depend on the solvent being used
Polar molecules will be more strongly attracted to polar solvents an so will move further
What is the stationary phase of chromatography
The paper
What is the mobile phase of chromatography
The solvent
What are the 3 main pieces of information that can be taken from a gas chromatogram
The number of compounds in the mixture
How much of each compound in present
The retention time
What the the number of compounds in a mixture represented by on a gas chromatogram
The number of peaks
What is how much of each compound is present represented by on a gas chromatogram
The height if the peak (higher = more)
What is the retention time represented by on a gas chromatogram
The position of the peak
What is the line at the bottom of the chromatography paper called
The baseline
What is the line where the solvent stops called
The solvent front
How do you calculate the Rf value
Rf = distance travelled by compound / distance travelled by solvent front
Name a use of chromatography
Law enforcement (compares a sample found at a crime scene to samples from suspects)
