Chromatography

Question 1

How does TLC work?

Answer 1

The stationary phase is solid and the mobile phase is liquid solvent, the mixture is dissolved in the mobile phase and its components are adsorbed on to its surface or the solid with differing strengths

Question 2

How do you calculate the Rf value?

Answer 2

Distance moved my component/ distance moved by liquid mobile phase front

Question 4

How does GC work?

Answer 4

The stationary phase is either solid or liquid and the mobile phase is an inert carrier gas, the mixture to be separated is also gaseous and it’s components are either adsorbed onto the surface of the solid stationary phase with different strengths or having different solubility in the liquid stationary phase

Question 5

What is the relention time?

Answer 5

How long it takes the component in the mixture to pass from one end of the column to a detector at the other end (characteristic for a particular substance)

Question 6

What is the peak area?

Answer 6

Is proportional to the amount of component present in the mixture and can be used to find concentrations or unknowns

Question 7

What are the limitations to gas chromatography?

Answer 7

Similar compounds often have similar retention times so it’s difficult to distinguish
Completely new unknown compounds have no reference retention times for comparison

Question 8

What are calibration curves used for?

Answer 8

Can be created to confirm concentrations of components