Coordination Compounds
For Student Groups
Complex compounds seldom feature in chemistry lessons, but often in everyday life. Because many of them are coloured, they are found in plants and foodstuff, they play an important role in chemical detection reactions and find many uses in industry – from decoration to counterfeit protection.
- Age
- 16 to 20 years
- Duration
- 1 day
- Maximum number of participants
- 20
Experiments
- Photometric determination of the coordination number of a copper complex
- Complex compounds in laboratory and nature (e.g. chlorophyll)
- Detection reactions (iron and calcium detection, nickel detection in coins, sugar detection with Fehling's reagent, detection of fluorides in toothpaste)
- Preparation and use of complexes (copper chlorophyll, ‘Prussian Blue’)
In this course, participants are introduced to the phenomenon of coordination compounds in two different ways. A qualitative part focuses on the occurrence, production, properties and application of coordination compounds demonstrated by simple experiments. For example, the students isolate plant pigments by extraction, separate the ingredients by thin layer chromatography and observe the different color and fluorescence properties of chlorophyll and phaeophytin (chlorophyll without the coordinated magnesium ion). They also perform various detection reactions relying on formation of colored complex compounds. The quantitative part consists – in addition to the experimental distinction between ionic and complex compounds – of the photometric determination of the coordination number of a copper-ammine complex.