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 interact irreversibly with the analyte.
- BColumns containing more theoretical plates take a long time to perform separations.
- CColumns containing more theoretical plates lend themselves to component mixing.
- DColumns containing more theoretical plates are better suited to separate a complex mixture.
- EColumns containing more theoretical plates make separations impossible.
Which of the following does reversed-phase chromatography refer to?
- AA nonpolar stationary phase and a polar mobile phase
- BA stationary phase and a mobile phase of similar polarities
- CA polar stationary phase and a nonpolar mobile phase
- DA polar stationary phase and a polar mobile phase
- EA nonpolar stationary phase and a nonpolar mobile phase
When separating a mixture by column chromatography, which of the following steps is not required?
- AThe solvent mixture is selected to ensure good component separation.
- BAll collected fractions are analyzed by thin-layer chromatography.
- CAn eluent is passed through the column before adding the sample.
- DThe solid phase is placed above a wool plug or glass frit.
- EAn eluent is added to the top of the column to prevent drying.