Amalgam sample
The amalgam sample is a preliminary test for mercury salts in analytical-inorganic chemistry . For this purpose, a nitric acid sample solution is placed on a copper sheet - what remains is a silvery amalgam stain that cannot be wiped off:
- Redox reaction : mercury cations and elemental copper oxidize to copper cations and elemental mercury.
Instead of a nitric acid solution, hydrochloric acid and sodium chlorate can also be added to the solid sample.
The mercury forms an alloy with the copper sheet , the copper amalgam . This is initially gray and becomes shiny silver when rubbed.
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If silver is present in the sample, it is also deposited. To distinguish it, you can heat the piece of copper so that the mercury evaporates and is deposited on a watch glass held nearby. The droplets can then be seen with a microscope.
literature
- Jander-Blasius: Introduction to the inorganic-chemical internship , 14th edition, S. Hirzel Verlag, Stuttgart, 1995, ISBN 3-7776-0672-3
Web links
Wikibooks: Internship Inorganic Chemistry / Mercury # Amalgan Sample - Learning and teaching materials