Flashcards
F324-Module 3-Chromatography
Flashcards do conjunto (18)
- 1What is chromatography?Chromatography is an analytical technique used to separate the components in a mixture.
- 21. Who was the scientist who invented 'chromatography' in the early 1900's? 2. What experiment was he doing using chromatography?1. Mikhail Semyonvich Tsvet
2. Separate pigments in plant leaves. - 3What Greek words does chromatography originate from and what are the meanings of these words?'Chroma' meaning colour and 'graphein' meaning to write.
- 4Describe generally how the process of chromatography is carried out.1. Chromatography plate placed in chromatography tank with the sample line toward the bottom.
2. Plate in contact with the solvent with solvent level below sample.
3. Tank is covered and the plate is left until the solvent has reached the top of the plate.
4. Plate removed and solvent front marked.
5. Solvent allowed to evaporate and plate analysed. - 5What are three uses of chromatography in daily life?1. Analysis of drugs
2. Analysis of plastics
3. Analysis of flavourings
4. Analysis of foods
5. Analysis of pesticides
6. Analysis of forensic evidence
7. Analysis of fuels
8. Analysis air samples
9. Analysis water samples - 6What are three advantages of using chromatography as a method of analysis?1. It is a very versatile method of analysis
2. Components with similar physical properties in very complex mixtures can be separated.
3. Only small sample sizes are needed.
4. After separation, the pure components can be analysed precisely by other analytical methods. - 7What are the two different types of chromatography?Thin layer chromatography (TLC)
Gas chromatography (GC) - 8What is a 'phase' in chromatography?A phase in chromatography is a physically distinctive form of a substance, such as the solid, liquid, and gaseous states of ordinary matter.
- 9What is a 'mobile phase' in chromatography?The mobile phase is the phase that moves in chromatography. The mobile phase sweeps a mixture over the stationary phase.
- 10What is a 'stationary phase' in chromatography?The stationary phase in chromatography is the phase that does not move.
- 11What is the stationary phase and mobile phase in: 1. Thin layer chromatography 2. Gas chromatography1. Stationary phase is a solid on a solids support, mobile phase is a liquid.
2. Stationary phase is liquid/ solid on a solid support, mobile phase is a gas. - 12Chromatography works on the basis that different __________ have different ________ for a stationary phase and for a mobile phase.components
affinities - 13How does a components affinity for the stationary phase cause chromatography?The stationary phase interacts with the components in the mixture, slowing them down. The greater the interaction, the more the components are slowed down. This allows different components to flow over the stationary phase at different speeds separating the components.
- 14How does a solid stationary phase separate by?Adsorption
- 15What is 'adsorption'?Adsorption is the process by which a solid holds/binds to molecules of a gas or liquid or solute as a thin film on the SURFACE of a solid or, more rarely, a liquid.
- 16How does a liquid stationary phase separate by?Relative solubility
- 17How do components separate by relative solubility?Some components dissolve more readily in the liquid and these are slowed down more than components with lower solubility.
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- A-Level Chemistry A2 FlashCards sobre F324-Module 3-Chromatography, criado por Serena Mirpuri em 09-04-2016.
- Criado por
- Serena Mirpuri
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