Quelpr
1 markInfrared Spectroscopy

CAPE Chemistry Unit 2 · 2013 · Paper 2 · Question 2(c)(iii)b)

Figures 2, 3, and 4 show IR spectra for 2-propanol (CH3CH(OH)CH3), butanoic acid (CH3CH2CH2COOH), and acetone (CH3COCH3).

Justify your identification of Compound C by indicating which absorption band on the spectrum was used and specifying the functional group responsible.

This question uses a figure or table from the paper — you'll see it when you practise.

The mark scheme is shown once you've answered.

Practise this question

Other parts of this question

  1. 2(a)State two molecular characteristics required for a molecule to be suitable for analysis by infrared (IR) spectroscopy.[2 marks]
  2. 2(b)Give two examples of practical applications of IR spectroscopy.[2 marks]
  3. 2(c)(i)a)Identify Compound A from its IR spectrum shown in Figure 2.[1 mark]
  4. 2(c)(i)b)Justify your identification of Compound A by indicating which absorption band on the spectrum was used and specifying the functional group responsible.[1 mark]
  5. 2(c)(ii)a)Identify Compound B from its IR spectrum shown in Figure 3.[1 mark]
  6. 2(c)(ii)b)Justify your identification of Compound B by indicating which absorption band on the spectrum was used and specifying the functional group responsible.[1 mark]
  7. 2(c)(iii)a)Identify Compound C from its IR spectrum shown in Figure 4.[1 mark]
  8. 2(d)(i)Describe four steps involved in preparing and analysing a solid sample using IR spectroscopy.[4 marks]
  9. 2(d)(ii)Explain why the sample plates used in IR spectroscopy are made of NaCl.[1 mark]

More practice: the rest of this paper · more Infrared Spectroscopy questions · all CAPE Chemistry Unit 2 past papers