Question

1.define IR spectroscopy technique,

A.explain what kind of samples can and are ananlysed and how its annlysed

B.explain if its possible for the technique to distinguish enantimers and how.

C.how can this technique be used in forensic science

Answer 1

1) IR spectroscopy is a tool to study interaction of infrared light with a matter. It is used to identify the functional group in a molecule.

A) For the compounds to be IR active, there must be a change in the dipole moment of the molecule. Symmetric molecules do not absorb IR radiation since there is no dipole moment. For example carbon dioxide ( O=C=O).

B) Enantiomers are the isomers which only differ in their optical rotation. Therefore they cannot be distinguished by IR spectroscopy since IR energy has no chirality.

C) Generally at crime scenes, common evidences found are hair fibres.IR technique is used to differentiate between normal and chemically treated (bleaching) hair.