MCQOPTIONS
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MCQOPTIONS
This section includes 40 Mcqs, each offering curated multiple-choice questions to sharpen your Analytical Instrumentation knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Column bleeding occurs when |
| A. | elution of the analyte is extended over time |
| B. | the column is cracked and stationary phase leaks out |
| C. | traces of the stationary phase are eluted |
| D. | the column breaks during installation and causes personal injury |
| Answer» D. the column breaks during installation and causes personal injury | |
| 2. |
Which of the following are not used as stationary phases in a GC column? |
| A. | Polysiloxanes |
| B. | Silica |
| C. | Cyclodextrins |
| D. | None are used as stationary phases |
| Answer» C. Cyclodextrins | |
| 3. |
Sample retention in the column is measured by |
| A. | retention time |
| B. | retention factor |
| C. | retention index |
| D. | all of these |
| Answer» E. | |
| 4. |
Sample injection is considered successful if |
| A. | all of the sample in the injector has been added to the column |
| B. | the sample is concentrated at the start of the column |
| C. | the sample is spread evenly along the column |
| D. | the sample is homogenously spread along the column |
| Answer» C. the sample is spread evenly along the column | |
| 5. |
Which of the following gases is unsuitable for use as a GC carrier gas? |
| A. | Nitrogen |
| B. | Helium |
| C. | Oxygen |
| D. | All of the above |
| Answer» D. All of the above | |
| 6. |
Doubling the column's length increases resolution by a factor of |
| A. | (2)0.5 |
| B. | 2 |
| C. | 3 |
| D. | 4 |
| Answer» B. 2 | |
| 7. |
What does the retention factor, k', describe? |
| A. | The distribution of an analyte between the stationary and the mobile phase |
| B. | The migration rate of an analyte through a column |
| C. | The velocity of the mobile phase |
| D. | All of these |
| Answer» C. The velocity of the mobile phase | |
| 8. |
Given below is the block diagram of gas chromatography. Identify the unmarked component. |
| A. | Pumping system |
| B. | Pressure regulator |
| C. | Flow regulator |
| D. | Sample injection system |
| Answer» E. | |
| 9. |
Which of the following is the disadvantage of coiled or helical shaped packed chromatographic column? |
| A. | It cannot be packed uniformly |
| B. | It cannot be repacked easily |
| C. | It is not compact |
| D. | It is not easy to heat it evenly |
| Answer» C. It is not compact | |
| 10. |
Which of the following is the advantage of a straight packed column? |
| A. | It can be packed uniformly |
| B. | It can be repacked easily |
| C. | It is compact |
| D. | It is easier to heat it evenly |
| Answer» D. It is easier to heat it evenly | |
| 11. |
Which of the following is the commonly used support material for the packed column in gas chromatography? |
| A. | Glass |
| B. | Metal |
| C. | Diatomaceous earth |
| D. | Stainless steel |
| Answer» D. Stainless steel | |
| 12. |
Slow injection of large samples leads to band broadening and loss of resolution. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 13. |
Which of the following is the disadvantage of nitrogen, which can be used as carrier gas in gas chromatography? |
| A. | Dangerous to use |
| B. | Expensive |
| C. | Reduced sensitivity |
| D. | High density |
| Answer» D. High density | |
| 14. |
Which of the following is the disadvantage of helium, which can be used as carrier gas in gas chromatography? |
| A. | Dangerous to use |
| B. | Expensive |
| C. | Reduced sensitivity |
| D. | High density |
| Answer» C. Reduced sensitivity | |
| 15. |
In column switching chromatography |
| A. | one column is removed and replaced by another |
| B. | compounds trapped on one column are eluted to another column |
| C. | any of the above |
| D. | the flow to the column is switched on and off repeatedly |
| Answer» B. compounds trapped on one column are eluted to another column | |
| 16. |
What does the selectivity factor describe? |
| A. | The maximum number of different species which a column can separate simultaneously |
| B. | The proportional difference in widths of two chromatographic peaks |
| C. | None of the above |
| D. | The relative separation achieved between two species |
| Answer» E. | |
| 17. |
What are the benefits of decreasing the column internal diameter? |
| A. | Increased resolution |
| B. | Increased sample capacity |
| C. | All of the above |
| D. | Reduced risk of column overloading |
| Answer» B. Increased sample capacity | |
| 18. |
What is the typical internal diameter of fused silica capillary columns? |
| A. | 0.3-0.5mm |
| B. | 0.2-0.3 mm |
| C. | 1.0-2.0 mm |
| D. | 0.5-1.0 mm |
| Answer» C. 1.0-2.0 mm | |
| 19. |
Helium is generally preferred as carrier gas over nitrogen and hydrogen because |
| A. | it has a lower viscosity |
| B. | it is inert |
| C. | all of above |
| D. | it doubles up as a party gas for balloons and funny voices |
| Answer» D. it doubles up as a party gas for balloons and funny voices | |
| 20. |
Headspace analysis is carried out in order to |
| A. | determine the psychological state of the tutor |
| B. | analyse volatile compounds from solid or liquid samples |
| C. | determine non-volatiles |
| D. | analyse the column contents ahead of the sample |
| Answer» C. determine non-volatiles | |
| 21. |
What useful information can be found from a Van Deemter plot? |
| A. | Optimum mobile phase flow rate |
| B. | The selectivity factor |
| C. | Optimum column length |
| D. | Optimum column temperature |
| Answer» B. The selectivity factor | |
| 22. |
What does the retention factor, k\', describe? |
| A. | The migration rate of an analyte through a column |
| B. | The distribution of an analyte between the stationary and the mobile phase |
| C. | All of these |
| D. | The velocity of the mobile phase |
| Answer» B. The distribution of an analyte between the stationary and the mobile phase | |
| 23. |
Which of the statements is correct? |
| A. | Gas chromatography is used to analyse solids |
| B. | Gas chromatography is used to analyse gases |
| C. | All of the above |
| D. | Gas chromatography is used to analyse gases, solutions and solids |
| Answer» D. Gas chromatography is used to analyse gases, solutions and solids | |
| 24. |
Which of these effects result from slow injection of a large sample volume? |
| A. | Decreased resolution |
| B. | Increased resolution |
| C. | Constant resolution |
| D. | Non-linear detector response |
| Answer» B. Increased resolution | |
| 25. |
Which of the following detectors give concentration-dependent signals? |
| A. | Thermal conductivity |
| B. | Electron-capture detector |
| C. | All of these |
| D. | Infra-red detector |
| Answer» D. Infra-red detector | |
| 26. |
Split injection is carried out by |
| A. | splitting the sample into smaller portions to inject at the same time through parallel ports |
| B. | splitting the sample into smaller portions to inject sequentially |
| C. | none of the above |
| D. | splitting off some of the sample so that it does not enter the column |
| Answer» E. | |
| 27. |
Derivatisation of a sample is carried out to |
| A. | increase the detector response |
| B. | reduce polarity of the analytes |
| C. | all of the above |
| D. | increase volatility of the analytes |
| Answer» D. increase volatility of the analytes | |
| 28. |
Resolution is proportional to the |
| A. | square root of the number of theoretical plates in a column |
| B. | number of theoretical plates in a column |
| C. | cube root of the number of theoretical plates in a column |
| D. | square of the number of theoretical plates in a column |
| Answer» B. number of theoretical plates in a column | |
| 29. |
The GC trace obtained after an experiment is called a |
| A. | chromatogram |
| B. | chromatograph |
| C. | graph |
| D. | chromatophore |
| Answer» B. chromatograph | |
| 30. |
WHICH_OF_THE_FOLLOWING_IS_THE_COMMONLY_USED_SUPPORT_MATERIAL_FOR_THE_PACKED_COLUMN_IN_GAS_CHROMATOGRAPHY??$ |
| A. | Glass |
| B. | Metal |
| C. | Diatomaceous earth |
| D. | Stainless steel |
| Answer» D. Stainless steel | |
| 31. |
Which of the following is the disadvantage of coiled or helical shaped packed chromatographic column?$ |
| A. | It cannot be packed uniformly |
| B. | It cannot be repacked easily |
| C. | It is not compact |
| D. | It is not easy to heat it evenly |
| Answer» C. It is not compact | |
| 32. |
Which of the following is the advantage of straight packed column?$ |
| A. | It can be packed uniformly |
| B. | It can be repacked easily |
| C. | It is compact |
| D. | It is easier to heat it evenly |
| Answer» D. It is easier to heat it evenly | |
| 33. |
Which of the following is not a desirable feature of the ovens used in gas chromatography? |
| A. | It must have a fast rate of heating |
| B. | Power consumption should be kept low |
| C. | It must have maximum thermal gradients |
| D. | It should have proper insulation |
| Answer» D. It should have proper insulation | |
| 34. |
Sample injection port must be maintained at a temperature at which rapid vapourisation occurs but thermal degradation does not occur. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 35. |
Capillary columns are open tubular columns constructed from which of the following materials? |
| A. | Glass |
| B. | Metal |
| C. | Stainless steel |
| D. | Fused silica |
| Answer» E. | |
| 36. |
What must be done to the solid samples for it to be introduced into the column without using solid injection syringes in gas chromatography? |
| A. | Introduced in hot-zone of the column |
| B. | Dissolved in volatile liquids |
| C. | Introduced using rotary sample valve |
| D. | Introduced using sampling loops |
| Answer» C. Introduced using rotary sample valve | |
| 37. |
In which of the following methods are liquid samples injected into the column in gas chromatography? |
| A. | Gas tight syringe |
| B. | Micro-syringe |
| C. | Rotary sample valve |
| D. | Solid injection syringes |
| Answer» C. Rotary sample valve | |
| 38. |
Which of the following is the disadvantage of hydrogen, which can be used as carrier gas in gas chromatography? |
| A. | Dangerous to use |
| B. | Expensive |
| C. | Reduced sensitivity |
| D. | High density |
| Answer» B. Expensive | |
| 39. |
Which of the following is not a feature of carrier gas used in gas chromatography? |
| A. | It must be chemically inert |
| B. | It should be suitable for the detector employed |
| C. | It should not be completely pure |
| D. | It should be cheap |
| Answer» D. It should be cheap | |
| 40. |
For the separation of which of the following substances, Gas-solid chromatography is being used? |
| A. | Thermally stable organic components |
| B. | Volatile organic components |
| C. | Thermally stable inorganic components |
| D. | Low molecular weight gaseous species |
| Answer» E. | |