CHROMATOGRAPHY

CHROMATOGRAPHY Paper Chromatography Column Chromatography Thin Layer Chromatography Gas Chromatography Size Exclusion Chromatography Ion Exchange Chromatography

Q1. Characteristic feature of any form of chromatography is the ___

A. Use of molecules that are soluble in water.B. Use of an inert carrier gas.C. Calculation of an Rf value for the molecules separated.D. Use of a mobile and a stationary phase.Answer- D

Q2. A student sets up a paper chromatogram and places a spot of food dye on the origin. After six minutes the solvent has moved 12 cm and a blue spot has advanced 9 cm. After fourteen minutes the solvent has advanced a further 8 cm. How many cm from the origin is the blue spot likely to beA. 26B. 8C.18D.15

Answer- D

Q3. Thin layer chromatography can be used to distinguish between different amino acids. If a particular amino acid has low solubility in the mobile phase used, then the amino acid

A. Will have a low Rf value.B. Will spend more time dissolved in the mobile phase than attached to the stationary phase.C. Will move at a speed close to that of the solvent. D. Must have a high molecular massAnswer- A

Q4. Which of the following is the most suitable gas to use as a carrier gas in a gas chromatogram?A. HeliumB. OxygenC. MethaneD. Carbon dioxide

Answer- A

Gas / Thermal ConductivityHydrogen 45.9Helium 36.9Neon 11.8Methane 8.6Oxygen 6.6Air 6.4Nitrogen 6.4CO 6.2Water 4.5Argon 4.5CO2 4.2

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Q5. A new youth drink contains sugar, salt, alcohol and vitamin C. A gas chromatogram could be used to determine the

A. Alcohol content only.B. Alcohol, sugar and vitamin C content onlyC. Concentration of all ingredients in the drink. D. Alcohol and sugar content only.Answer- A

Q6. Which of the following statements about paper and gas chromatography is correct?A. The Rf and Rt values of a substance are determined solely by the interaction of the substance with the stationary phase.B. A substance with a long retention time in gas chromatography is likely to have a high Rf value in paper chromatography.C. A high Rf value is indicative of a substance that adsorbs strongly onto the stationary phaseD. A long retention time in gas chromatography is indicative of a substance with a strong adsorption on to the stationary phase.

Answer- D

Q7. Paper chromatography is

A. Partition ChromatographyB. Adsorption chromatographyC. Electrical mobility of ionic species D. None of the above.Answer- A

Q8. In reverse phase chromatography, the stationary phase is madeA. Non-polarB. PolarC. Either non-polar or polarD. Semi polarAnswer- A

Q9. Ion exchange chromatography is based on the

A. Electrostatic attraction B. Electrical mobility of ionic species C. Adsorption chromatography D. Partition chromatographyAnswer- A

Q10. Which would be best to separate a protein that binds strongly to its substrate? A. Gel filtration B. Affinity chromatographyC. Cation exchange D. Anion exchangeAnswer- A

Q11. The composition of Silica gel G is A. Silica gel without binder B. Silica gel + CaSO4 C. Silica gel + alumina D. silica gel + MgSO4Answer- B

Q12. Retention factor or Retardation factor (Rf) value ranges fromA. 0 to 1 B. 0 to 2.0 C. +2 to -2D. +1 to -1

Answer- A

Q13. Sucrose can be determined after silylation using which chromatographic technique

A. HPLC B. Gel chromatography C. Gas liquid chromatography D. Paper chromatography Answer- C

Silyl derivatives are generally less polar and more volatile and more thermally stable than their precursor organic compound.

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Q14. Which of the following can not be used as carrier gas in GC?A. HydrogenB. NitrogenC. HeliumD. OxygenAnswer- D

Q15. Retention time is defined as

A. Time needed for an individual analyte to be elute 50%B. Time needed for all solutes in a sample to be eluted C. Time needed for complete elution of analyte from the ColumnD. Time needed for complete elution of analyte from the DetectorAnswer- A

Q16. For better resolution which category of whattman filter paper is used A. Grade No 20B. Grade No 4C. Grade No 540D. Grade No 3

Answer- A

Q17. Which of the following is used as a detectors in GC

A. TCD & FIDB. AID & ECDC. Both A & BD. KatherometerE. All the AboveAnswer- E

Q18. LALLS Detectors used inA. Gas ChromatographyB. Column ChromatographyC. Size Exclusion ChromatographyD. Ion Exchange Chromatography

Answer- C

Q19. Which type of chromatographic process requires that when materials that cannot be readily dissolved in a solvent for chromatography need to be heated or pyrolyzed to a high temperature?

A. Gas chromatography B. High-performance liquid chromatography C. Thin-layer chromatography D. Pyrolysis can be used for any and all chromatographic processes

Answer- A

Q20. The higher the solubility of a gas in a liquid, the greater the tendency of the gas molecules to:A. Remain in the liquid phase. B. Move from a liquid phase to a gaseous or vapor phaseC. Move from a liquid phase to a solid stateD. Disperse.

Answer- A

Q21. By adding SDS (sodium dodecyl sulfate) during the electrophoresis of proteins,itis possible to:

A. Determine a proteins iso electric pointB. Determine an enzymes specific activityC. Determine the amino acid composition ofthe protein.D. Separate proteins exclusively on the basis of molecular weightAnswer- D

Q22. Nucleic acidcan beseparated onA. Silica gel ChromatographyB. SDS-PAGEC. Agarose GelsD. Polythelene GelE. All the above

Answer- E

For nucleic acids,ureais the most commonly used denaturant. For proteins,sodium dodecyl sulfate(SDS) is an anionic detergent applied to protein sample to linearize proteins and to impart a negative charge to linearized proteins. This procedure is calledSDS-PAGE. In most proteins, the binding of SDS to the polypeptide chain imparts an even distribution of charge per unit mass, thereby resulting in a fractionation by approximate size during electrophoresis.23

Q23. Which detector ispreferably used in forthe identification of halogenated compounds

A. Ultraviolet detectorB. Electron CapturedetectorC. Thermal conductivityD. Mass spectrophotometer-detectorAnswer- B

Q24. The following isnot an example ofPartition chromatographyA. TLCB. Gas ChromatographyC. Paper ChromatographyD. High Performance Liquid ChromatographyE. Both B & D

Answer- C