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Phase Separations · CAPE Chemistry Unit 2

42 past-paper questions on Phase Separations, part of Analytical Methods and Separation Techniques, from every CAPE Chemistry Unit 2 paper on Quelpr.

Practise Phase Separations
  1. 3(a)(iii)2 marks· CAPE Chemistry Unit 2 · 2005 · Paper 2Briefly describe a simple laboratory method to determine the relative percentage alcohol in TWO home-made beverages.
  2. 5(c)(i)3 marks· CAPE Chemistry Unit 2 · 2009 · Paper 2Suggest TWO advantages and ONE disadvantage of using steam for the extraction process illustrated in Figure 5.
  3. 5(c)(ii)2 marks· CAPE Chemistry Unit 2 · 2009 · Paper 2Explain what effect the length of the extractor in Figure 5 will have on the distillation process.
  4. Q261 mark · multiple choice· CAPE Chemistry Unit 2 · 2012 · Paper 1Which of the following statements about the partition coefficient may be true? I. It does not vary with temperature. II. The solute has to be in the same molecular state in both solvents for it to be a constant. III.…
  5. Q291 mark · multiple choice· CAPE Chemistry Unit 2 · 2012 · Paper 1A solution of 10\text{ g} of a carboxylic acid (weak acid) in 100\text{ cm}^3 of water is shaken with 100\text{ cm}^3 of ethoxyethane. It is found that only 6.5\text{ g} of the acid remains in aqueous solution…
  6. 5(a)5 marks· CAPE Chemistry Unit 2 · 2012 · Paper 2State the names and functions of the pieces of apparatus shown in Figure 2 and Figure 3.
  7. 5(b)(i)1 mark· CAPE Chemistry Unit 2 · 2012 · Paper 2Write an equation to explain the term 'partition coefficient' or 'distribution coefficient' using the example of an ester dissolved in a mixture of water and toluene.
  8. 5(b)(ii)2 marks· CAPE Chemistry Unit 2 · 2012 · Paper 2State TWO factors which affect the value of the partition coefficient.
  9. 5(b)(iii)4 marks· CAPE Chemistry Unit 2 · 2012 · Paper 2Explain the principles of solvent extraction with respect to the recovery of an organic compound from an aqueous solution.
  10. 5(b)(iv)3 marks· CAPE Chemistry Unit 2 · 2012 · Paper 2A solution of 10.0 g of an ester, Y, in 100 cm3 of water was shaken with 200 cm3 of ether. After separation, the aqueous solution was found to contain 1.6 g of Y. Calculate the partition coefficient of Y between ether…
  11. Q301 mark · multiple choice· CAPE Chemistry Unit 2 · 2013 · Paper 1Which of the following statements about partition coefficient would be true? I. It does not vary with temperature. II. The solute has to be in the same molecular state in both solvents for it to be a constant. III. The…
  12. 5(a)2 marks· CAPE Chemistry Unit 2 · 2013 · Paper 2Define the term 'partition coefficient'.
  13. 5(b)4 marks· CAPE Chemistry Unit 2 · 2013 · Paper 2When butanedioic acid was shaken with a mixture of water and ether, 10 cm³ of water contained 0.854 g of the acid while a similar volume (10 cm³) of ether contained 0.159 g. In a separate experiment, 10 cm³ of water and…
  14. 5(c)(i)1 mark· CAPE Chemistry Unit 2 · 2013 · Paper 2Suggest an appropriate separation technique to separate eucalyptus oil from an aqueous suspension of its leaves.
  15. 5(c)(ii)1 mark· CAPE Chemistry Unit 2 · 2013 · Paper 2Suggest an appropriate separation technique to isolate penicillin (organic solid) from an aqueous solution.
  16. 5(c)(iii)1 mark· CAPE Chemistry Unit 2 · 2013 · Paper 2Suggest an appropriate separation technique to separate the components of a coal tar residue.
  17. 5(c)(iv)1 mark· CAPE Chemistry Unit 2 · 2013 · Paper 2Suggest an appropriate separation technique to purify ethoxyethane from an impure source.
  18. 5(d)5 marks· CAPE Chemistry Unit 2 · 2013 · Paper 2Use the boiling point-composition phase diagram in Figure 6 to explain the principles of fractional distillation, starting with a liquid mixture of composition x.
  19. Q281 mark · multiple choice· CAPE Chemistry Unit 2 · 2014 · Paper 1Which of the following mixtures CANNOT be completely separated by fractional distillation?
  20. Q291 mark · multiple choice· CAPE Chemistry Unit 2 · 2014 · Paper 1Which of the following statements about the partition coefficient may be true? I. It does not vary with temperature. II. The solute has to be in the same molecular state in both solvents for it to be a constant. III.…
  21. Q291 mark · multiple choice· CAPE Chemistry Unit 2 · 2016 · Paper 1Which of the following diagrams shows the boiling point-composition curve for a minimum boiling point azeotrope for a mixture of A and B?
  22. Q301 mark · multiple choice· CAPE Chemistry Unit 2 · 2016 · Paper 1Which of the following features are advantages of steam distillation? I. It occurs under reduced pressure. II. The components do not decompose. III. It provides savings in fuel cost.
  23. 5(a)(i)2 marks· CAPE Chemistry Unit 2 · 2016 · Paper 2State Raoult's law for an ideal mixture of two liquids.
  24. 5(a)(ii)2 marks· CAPE Chemistry Unit 2 · 2016 · Paper 2List TWO characteristics of an ideal solution.
  25. 5(b)(i)1 mark· CAPE Chemistry Unit 2 · 2016 · Paper 2Define the term 'azeotropic mixture'.
  26. 5(b)(ii)1 mark· CAPE Chemistry Unit 2 · 2016 · Paper 2State ONE reason why azeotropes are NOT compounds.
  27. 5(b)(iii)6 marks· CAPE Chemistry Unit 2 · 2016 · Paper 2Using the graph showing the composition of a minimum boiling point mixture, explain clearly the result of distilling a mixture of Composition X as indicated.
  28. 5(c)3 marks· CAPE Chemistry Unit 2 · 2016 · Paper 2An aqueous solution contains 2.5 g of a compound in 50 cm³ of solution. The partition coefficient of the compound between water and an organic solvent is 0.200. Calculate the mass of the compound extracted by shaking…
  29. 2(b)1 mark· CAPE Chemistry Unit 2 · 2017 · Paper 2Suggest a separation technique that would be MOST effective in the extraction of eugenol (oil) from cloves (plant) in its natural source.
  30. 2(c)(i)3 marks· CAPE Chemistry Unit 2 · 2017 · Paper 2From Figure 1, list the letters of THREE pieces of apparatus that could be used in solvent extraction.
  31. 2(c)(i)2 marks· Chemistry · Unit 2 Q2 2(c)(i)Compare the arrangement of particles in solids with the arrangement of particles in liquids.
  32. 2(c)(ii)2 marks· Chemistry · Unit 2 Q2 2(c)(ii)When solid iodine is heated, a purple coloured gas is observed. State the process which occurs and give ONE example of another compound which undergoes the same process.
  33. 2(d)(i)5 marks· Chemistry · Unit 2 Q2 2(d)(i)Outline a series of steps indicating how this mixture can be separated, and the two components recovered, by the process of solvent extraction.
  34. 2(d)(ii)1 mark· Chemistry · Unit 2 Q2 2(d)(ii)State what is meant by the term 'partition coefficient'.
  35. 2(d)(iii)2 marks· Chemistry · Unit 2 Q2 2(d)(iii)If iodine is shaken with 100 cm³ of water and 100 cm³ of an organic solvent, the concentration of iodine in the water layer is 4.0 × 10⁻³ mol dm⁻³ and in the organic solvent is 1.0 × 10⁻² mol dm⁻³. Calculate the…
  36. 2(d)(iv)5 marks· Chemistry · Unit 2 Q2 2(d)(iv)The aqueous layer is separated and shaken with 50 cm³ of the pure organic solvent. Determine the concentration of iodine in the organic solvent at equilibrium in mol dm⁻³? Show ALL working.
  37. 2(f)(i)2 marks· Chemistry · Unit 2 Q2 2(f)(i)Explain the term 'solvent extraction'.
  38. 2(f)(ii)1 mark· Chemistry · Unit 2 Q2 2(f)(ii)State ONE use of solvent extraction.
  39. 2(f)(iii)2 marks· Chemistry · Unit 2 Q2 2(f)(iii)Describe what is meant by the term 'partition coefficient' as it relates to solvent extraction.
  40. 2(f)(iv)4 marks· Chemistry · Unit 2 Q2 2(f)(iv)Determine the mass of Q that will be extracted from 200 cm³ of aqueous solution containing 8 g of Q by shaking it with 50 cm³ of methylbenzene.
  41. 3(b)(iii)3 marks· Chemistry · Unit 2 Q3 3(b)(iii)Explain the principles involved in the fractional distillation of crude oil.
  42. 3(c)5 marks· Chemistry · Unit 2 Q3 3(c)Outline an experimental procedure that can be used to determine if Brand A white rum has a higher ethanol content than Brand B white rum.

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