A.1.1 State the reasons for using analytical techniques.
Qualitative analysis - detects the presence not quantity of a substance in a mixture. e.g substances in an athlete's blood
Quantitative analysis - measure the quantity of a substance in a mixture. e.g. alcohol in a driver's breath
Structural analysis - how the atoms are arranged in molecular structures. e.g. to determine the structure of a naturally occurring or artificial product.
A1.2 State that the structure of a compound can be determined by using information from a variety of analytical techniques singularly or in combination.
The techniques analyses the effect of different forms of energy on the substance.
Infrared spectroscopy - identifies the bonds in a molecule.
Mass spectroscopy - determines relative atomic and molecular masses. The fragmentation pattern is like a fingerprint, it identifies unknown substances or evidence for the arrangement of atoms in a molecule.
Nuclear magnetic resonance spectroscopy - shows the chemical environment of certain isotopes (hydrogen, carbon, phosphorus and fluorine) in a molecule, giving vital structural information.
**However, information from only one technique is usually insufficient to determine or confirm a structure.**
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