High-resolution mass spectrometry and chromatography Quiz
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5 questions, one answer each
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1. Why do two compounds with the same nominal Mr have different accurate Mr values?
- A. They have different numbers of neutrons in every atom
- B. Their molecules have different charges
- C. Isotope masses are not whole numbers, so different atom combinations have slightly different masses
- D. They are separated by chromatography
2. A spot moves 2.4 cm and the solvent front moves 6.0 cm. What is the Rf value?
- A. 0.40
- B. 0.25
- C. 2.5
- D. 0.60
3. What is the mobile phase in gas chromatography?
- A. A polar liquid
- B. Water
- C. A volatile solid
- D. An inert gas
4. What is the retention time in chromatography?
- A. The time the mass spectrometer takes to ionise a sample
- B. The time taken for a component to pass through the column to the detector
- C. The time for the solvent front to reach the top
- D. The time the sample is heated for
5. Which technique suits a mixture of non-volatile compounds?
- A. HPLC
- B. GC
- C. Neither
- D. Mass spectrometry alone