Worksheet: Column Chromatography
In this worksheet, we will practice describing purification by column chromatography, selecting mobile and stationary phases and troubleshooting errors.
Which of the following statements about columns containing more theoretical plates is true?
- AColumns containing more theoretical plates take a long time to perform separations.
- BColumns containing more theoretical plates make separations imposssible.
- CColumns containing more theoretical plates interact irreversibly with the analyte.
- DColumns containing more theoretical plates are better suited to separate a complex mixture.
- EColumns containing more theoretical plates lend themselves to component mixing.
What is the most common support material for a packed GC column?
- BSilica gel
- CFused silica
- DDiatomaceous earth
Reversed-phase chromatography refers to which of the following?
- AA nonpolar stationary phase and a nonpolar mobile phase
- BA stationary phase and mobile phase of similar polarities
- CA polar stationary phase and a nonpolar mobile phase
- DA nonpolar stationary phase and a polar mobile phase
- EA polar stationary phase and a polar mobile phase
When separating a mixture by column chromatography, which of the following steps is not required?
- AThe solid phase is placed above a wool plug or glass frit.
- BThe solvent mixture is selected to ensure good component separation.
- CEluent is added to the top of the column to prevent drying.
- DAll collected fractions are analysed by thin-layer chromatography.
- EEluent is passed through the column before adding the sample.