Chromatography

Question 1

What is the Rf value?

Answer 1

Rf = distance moved by substance / distance moved be solvent

Question 2

What does the area under a peak represent in GC?

Answer 2

Area under peak is proportional to the concentration of each component.

Question 3

What is the stationary phrase?

Answer 3

It is the chromatography paper.

Question 4

What is the mobile phase?

Answer 4

The solvent.

Question 5

What is chromatography used for?

Answer 5

Separates and analyses small amounts of mixtures.

Question 6

What is gas chromatography used for?

Answer 6

Separates volatile components in a mixture.

Question 7

How is solubility connected to TLC?

Answer 7

The more soluble a component is, the faster it travels.

Question 8

Why can comparisons of Rf values be difficult?

Answer 8

1. Components can have similar Rf values.

2. New substances have not got their Rf values recorded yet.

Question 9

What is retention time?

Answer 9

Is the x-axis.
The time it takes for a component to pass from the column inlet to the detector.

Is the amount of time between injecting the sample into the GC and the time it takes to come out/reach the detector.

Question 10

What is the mobile phase in GC?

Answer 10

An unreactive gas like He or N.

The GAS is in the mobile phase in GC.

Question 11

What is the stationary phase in GC?

Answer 11

Solid or liquid coating on a coiled tube.