Analytical Chemistry

Question 1

Define: mobile phase

Answer 1

The solvent in the chromatography process, which moves through the column or over the paper/thin layer

Question 2

Define: stationary phase

Answer 2

The immobile phase in chromatography that the mobile phase passes over or through.

Question 3

Paper chromatography:

• stationary phase
• mobile phase
• process of separation

Answer 3

Mobile phase: solvent
Stationary phase: water trapped between cellulose fibres of paper
Process: partition, calculate Rf value

Question 4

Thin layer chromatography:

• mobile phase
• stationary phase
• process of separation

Answer 4

Mobile phase: solvent
Stationary phase: thin solid layer which adsorbs solid molecules onto its surface (alumina or silica supported on inert base e.g. glass)
Process: adsorption (partitioning can occur if solid becomes rehydrated)

Question 5

HPLC

• moblie phase
• stationary phase
• process of separation

Answer 5

Mobile phase: high-purity solvent (usually polar, forced under pressure through column)
Stationary phase: non-volatile liquid bonded onto a solid support (column)
Process: partitioning, record retention time

Question 6

GLC

• mobile phase
• stationary phase
• process of separation

Answer 6

Mobile phase: inert carrier gas

Stationary phase: