Purification techniques crystallization sublimation distillation extraction chromatography - Question Bank
1. Which of the following is a common application of chromatography in organic chemistry?
2. What is the primary limitation of sublimation as a purification technique?
3. In extraction, if the desired compound is more soluble in the organic layer than the aqueous layer, which solvent would you choose for extraction from an aqueous solution?
4. Which technique is used to separate liquids that form azeotropes (mixtures with constant boiling points)?
5. What is the primary purpose of using a Buchner funnel and filter paper in crystallization?
6. Which of the following is a characteristic of a good solvent for crystallization?
7. The process of separating components of a mixture based on their different boiling points is known as:
8. Which method is used to purify solids that sublime easily, like iodine or naphthalene?
9. What is the primary advantage of using crystallization for purification?
10. In chromatography, the component that moves faster with the mobile phase is the one that has:
11. Which chromatographic technique is best suited for separating volatile compounds at high temperatures?
12. In crystallization, what is the process of removing dissolved impurities by washing the crystals with a small amount of cold solvent?
13. What is the purpose of a separatory funnel in the process of extraction?
14. When is steam distillation particularly useful for purifying essential oils from plant materials?
15. In fractional distillation, the fractionating column increases the surface area for repeated vaporizations and condensations, leading to better separation. What is commonly packed inside the column?
16. A mixture of camphor and naphthalene can be purified using which method?
17. Which of the following is a common application of sublimation in purification?
18. What is the primary advantage of crystallization over distillation for purifying solids?
19. Which purification technique relies on the principle of differential partitioning of a solute between two immiscible phases?
20. The process of separating a compound from a mixture by dissolving it in a suitable solvent is called:
21. What is the main advantage of using HPLC over traditional column chromatography?
22. In gas chromatography, the mobile phase is a:
23. Which type of chromatography is used for separating large biomolecules like proteins and nucleic acids based on size?
24. What is the role of the condenser in a distillation apparatus?
25. When separating a mixture of iodine and sand, which purification method is most effective?
26. Which technique is most appropriate for purifying volatile organic compounds that are thermally stable?
27. In crystallization, what is the term for a saturated solution that contains more dissolved solute than it theoretically should be able to hold at a given temperature?
28. What is the primary purpose of using an anti-bumping granule during distillation?
29. A compound that is more strongly adsorbed to the stationary phase will have a Rf value that is:
30. What does the Rf value represent in paper and thin-layer chromatography?
31. The separation in TLC is achieved by the differential migration of components on the stationary phase due to their interactions with the mobile phase. This is known as:
32. In Thin-Layer Chromatography (TLC), the stationary phase is coated on a:
33. Paper chromatography is a type of partition chromatography where the stationary phase is:
34. Which type of chromatography is used to separate compounds based on their differing affinities for the stationary and mobile phases?
35. The stationary phase in column chromatography is typically:
36. In chromatography, the mobile phase is:
37. What is the process of separating components of a mixture by passing it through a stationary phase?
38. Which of these is NOT a common solvent for recrystallization?
39. For effective recrystallization, the desired compound should be soluble in the solvent at high temperatures and insoluble at low temperatures. What is the opposite property desired for impurities?
40. What is the primary goal of recrystallization?
41. Which of the following is a common immiscible solvent pair used in extraction?
42. In solvent extraction, the separation is based on the difference in the:
43. Steam distillation is a useful technique for purifying which class of compounds?
44. Vacuum distillation is employed for purifying compounds that have which characteristic?
45. Which type of distillation is used to separate liquids with very close boiling points?
46. What is the main principle behind fractional distillation?
47. Simple distillation is primarily used to separate liquids with a significant difference in which property?
48. When can sublimation be effectively used as a purification method?
49. Which purification technique is most suitable for separating a solid solute from a liquid solvent when the solute is soluble in the solvent?