A1. There is a wide range of analytical techniques available to chemists.
(a) State two reasons why the use of analytical chemistry techniques is important in society today.
(b) Identify which analytical technique is regularly used for
(i) separation of a mixture of sugars.
(ii) 14C isotopic dating.
(iii) scanning of the human body to detect diseases such as cancer and multiple sclerosis.
A2. Infrared (IR) spectroscopy is widely used as a technique in analytical chemistry.
(a) Describe the operating principles of a double-beam infrared (IR) spectrometer.
(b) Explain what happens at a molecular level during the absorption of IR radiation by carbon dioxide, CO2.
(c) The IR spectrum, mass spectrum and 1H NMR spectrum of an unknown compound, X, of molecular formula C3H6O2 are as follows.
(i) Identify the bonds responsible for the peaks A, B and C in the IR spectrum of X.
(ii) In the mass spectrum of X, deduce which ions the m/z values at 74, 45 and 29 correspond to.
m/z = 74:
m/z = 45:
m/z = 29:
(iii) Identify the peak at 11.73 ppm in the 1H NMR spectrum.
(iv) Deduce the structure of X.