KEY POINTS:
- Qualitative analysis – the identification of substances – is one of the key fields of analytical chemistry. It’s essential we are able to determine one element or substance from another safely and with great accuracy.
- Modern day analytical chemistry has come a long way from the squeaky pop test – though simple laboratory tests are still useful as a costs saving exercise.
- The mass spectrometer easily identifies not only elements and their Relative Atomic Masses to many decimal places, but also identifies compounds. The mass spectrum of an element or compound is as unique as a fingerprint to us humans.
- V.I.A.D.D. – Vaporization, ionisation, acceleration, deflection and detection are the sequence of process that lead to relative abundances of isotopes being given.
- You are unlikely to find a mass spectrometer in the average high school classroom – a new one can cost upwards of US$20,000.
THINK OUTSIDE THE BOX:
- How many different elements can you identify in the laboratory using simple chemical tests?
- How many pieces of evidence do you think are required to say with absolute certainty what the identity of an unknown substance is?