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Ultra Violet-Visible (UV/VIS) Spectroscopy · CAPE Chemistry Unit 2

36 past-paper questions on Ultra Violet-Visible (UV/VIS) Spectroscopy, part of Analytical Methods and Separation Techniques, from every CAPE Chemistry Unit 2 paper on Quelpr.

Practise Ultra Violet-Visible (UV/VIS) Spectroscopy
  1. 3(b)(i)4 marks· CAPE Chemistry Unit 2 · 2007 · Paper 2Using the calibration curve of absorbance versus concentration provided in Figure 1, estimate the concentration of phosphate ion in each sample and complete Table 2.
  2. 2(c)(i)3 marks· CAPE Chemistry Unit 2 · 2010 · Paper 2State three steps that must be followed when preparing a sample of organic compound X for UV/VIS spectroscopic analysis at 200 nm.
  3. 2(c)(ii)2 marks· CAPE Chemistry Unit 2 · 2010 · Paper 2State two properties of complexing reagents that make them suitable for use in UV/VIS analysis.
  4. 5(a)(i)1 mark· CAPE Chemistry Unit 2 · 2011 · Paper 2State the source of absorption in UV/VIS spectroscopy.
  5. 5(a)(ii)3 marks· CAPE Chemistry Unit 2 · 2011 · Paper 2Use an energy level diagram to show the electronic transitions that can occur in UV/VIS spectroscopy.
  6. 5(b)(i)1 mark· CAPE Chemistry Unit 2 · 2011 · Paper 2Define the term 'chromophore'.
  7. 5(b)(ii)1 mark· CAPE Chemistry Unit 2 · 2011 · Paper 2Suggest the chromophore in naphthalene (P) that is responsible for the absorption of UV radiation.
  8. 5(b)(iii)3 marks· CAPE Chemistry Unit 2 · 2011 · Paper 2A sample of the solution in a cell of path length 1 cm gave an absorbance of 1.2 at a wavelength of 312 nm and an extinction coefficient of 288 dm³ mol⁻¹ cm⁻¹. Calculate the concentration of P in the solution.
  9. 5(c)4 marks· CAPE Chemistry Unit 2 · 2011 · Paper 2Explain the use of calibration curves and standard solutions in UV/VIS analysis.
  10. 5(d)2 marks· CAPE Chemistry Unit 2 · 2011 · Paper 2List TWO uses of UV/VIS spectroscopy in chemical analysis.
  11. Q231 mark · multiple choice· CAPE Chemistry Unit 2 · 2012 · Paper 1Which of the following types of electronic transitions would NOT produce absorption in the UV/VIS region of the spectrum?
  12. Q241 mark · multiple choice· CAPE Chemistry Unit 2 · 2012 · Paper 1Hexane will not absorb light in the UV/VIS region of the spectrum because there is a
  13. Q211 mark · multiple choice· CAPE Chemistry Unit 2 · 2013 · Paper 1The complex ion [\text{FeSCN}]^{2+} has a molar absorptivity (\varepsilon) of 7.0 \times 10^3\text{ dm}^3\text{ mol}^{-1}\text{ cm}^{-1}. The concentration of its solution, which gives an absorbance of 4.2 when…
  14. Q231 mark · multiple choice· CAPE Chemistry Unit 2 · 2013 · Paper 1The structural features which cause absorption in the UV/VIS region of the electromagnetic spectrum are known as
  15. Q251 mark · multiple choice· CAPE Chemistry Unit 2 · 2013 · Paper 1Which of the following alkenes has the wavelength of maximum absorption, \lambda_{\text{max}}?
  16. Q211 mark · multiple choice· CAPE Chemistry Unit 2 · 2014 · Paper 1The structural features which cause absorption in the UV/VIS region of the electromagnetic spectrum are known as
  17. Q221 mark · multiple choice· CAPE Chemistry Unit 2 · 2014 · Paper 1Which of the following alkenes has the wavelength of maximum absorption, \lambda_{\text{max}}?
  18. Q171 mark · multiple choice· CAPE Chemistry Unit 2 · 2015 · Paper 1Species which absorb light in the UV-Vis region have I. saturated bonds II. unsaturated bonds III. non-bonded electron pairs.
  19. Q181 mark · multiple choice· CAPE Chemistry Unit 2 · 2015 · Paper 1UV-Vis molecular absorption arises from vibrational and rotational transitions from I. within the ground state II. the ground state to the excited state III. the excited state to the ground state.
  20. Q231 mark · multiple choice· CAPE Chemistry Unit 2 · 2015 · Paper 1Which of the following relationships is TRUE for the absorbance, A, of UV-Vis light by a solution of concentration c?
  21. Q271 mark · multiple choice· CAPE Chemistry Unit 2 · 2015 · Paper 1What transitions are expected from \text{C}_4\text{H}_9\text{NO}_2 in a UV-Vis spectrum?
  22. Q221 mark · multiple choice· CAPE Chemistry Unit 2 · 2016 · Paper 1Which of the following types of electronic transitions would NOT produce absorption in the UV/VIS region of the spectrum?
  23. Q171 mark · multiple choice· CAPE Chemistry Unit 2 · 2017 · Paper 1Species which absorb light in the UV-Vis region have I. saturated bonds II. unsaturated bonds III. non-bonded electron pairs
  24. Q221 mark · multiple choice· CAPE Chemistry Unit 2 · 2017 · Paper 1The complex ion [\text{FeSCN}]^{2+} has a molar absorptivity (\varepsilon) of 7.0 \times 10^3\text{ dm}^3\text{ mol}^{-1}\text{ cm}^{-1}. The concentration of its solution, which gives an absorbance of 4.2 when…
  25. Q271 mark · multiple choice· CAPE Chemistry Unit 2 · 2017 · Paper 1What transitions are expected from \text{C}_6\text{H}_5\text{NO}_2 in a UV-Vis spectrum?
  26. 2(c)3 marks· Chemistry · Unit 2 Q2 2(c)On Figure 3, draw the possible transitions associated with the absorption in this UV/VIS region of the spectrum.
  27. 2(c)(i)3 marks· Chemistry · Unit 2 Q2 2(c)(i)Complete Figure 2 by inserting arrows to show ALL possible electron transitions in the molecular orbitals indicated.
  28. 2(c)(ii)3 marks· Chemistry · Unit 2 Q2 2(c)(ii)List the transitions from (c) (i) which will normally produce absorption in the ultraviolet and visible regions of the electromagnetic spectrum.
  29. 2(c)(iii)4 marks· Chemistry · Unit 2 Q2 2(c)(iii)The absorbance of an iron thiocyanate solution containing 0.005 mol Fe/mL was reported as 0.4900 at 540 nm. Using Beer–Lambert's law, A = εcl, calculate the specific absorptivity, including units, of iron thiocyanate,…
  30. 2(d)(i)1 mark· Chemistry · Unit 2 Q2 2(d)(i)State what would be observed when the ammonia is added.
  31. 2(d)(ii)1 mark· Chemistry · Unit 2 Q2 2(d)(ii)Give the reason why the wavelength of 615 nm was chosen.
  32. 2(d)(iii)3 marks· Chemistry · Unit 2 Q2 2(d)(iii)Describe how a calibration curve can be made and used in the analysis process.
  33. 2(e)(i)3 marks· Chemistry · Unit 2 Q2 2(e)(i)Calculate the concentration of the known Cu2+ ions, in mol/dm^3.
  34. 2(e)(ii)3 marks· Chemistry · Unit 2 Q2 2(e)(ii)Applying Beer-Lambert's law, calculate the molar absorptivity using the stated absorbance value.
  35. 2(e)(iii)1 mark· Chemistry · Unit 2 Q2 2(e)(iii)Calculate the concentration of the Cu2+ ions in this sample.
  36. 2(f)4 marks· Chemistry · Unit 2 Q2 2(f)Outline the steps in analysing a sample using UV/VIS spectroscopy.

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