1. Why is it important to seal the jar containing the TLC plate?
- to allow the process to occur
- to slow the evaporation of the solvent from the TLC plate
- to speed up evaporation of the solvent
- to prevent bacteria contaminating the sample
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Other questions in this quiz
2. Which is NOT a limitation of thin layer chromatography?
- may be difficult to find a solvent which will separate all components
- similar compounds have similar Rf values
- similar compounds have similar retention times
- unknown compounds have no Rf value for comparison
3. What does a liquid stationary phase separate by?
- relative solubility
4. What is the benefit of coupling gas chromatography with mass spectrometry
- gas chromatography separates compounds and mass spectra can be compared to a database
- both the retention time and mass spectra can be used to improve the reliability of the identification
- mass spectroscopy separates the compounds and retention times can be compared to a database
5. Which is NOT a limitation of gas chromatography?
- unknown compounds have no reference Rf value
- substances have the same retention times
- unknown compounds have no reference retention time
- substances can 'hide' beneath each other so will not be detected