Description of experiment
Below follows a plain text transcript of the selected experiment.
Needed compounds:
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hydrochloric acid : HCl
sulphuric acid : H2SO4
sodium biphosphate : NaH2PO4 . H2O
ferric ammonium sulfate hydrate : Fe NH4 (SO4)2 . 12H2O
Class:
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elem=Fe,P,Cl
coordination
Summary:
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Ferric ions form a colorless complex with phosphate ions in acidic
environments. In the presence of chloride ions, a yellow coordination
complex is formed, which can exist, even in the presence of phosphate.
Description:
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Dissolve some ferric ammonium sulfate in water: The liquid is (almost) clear
and yellow/brown.
Add a solution of sodium biphosphate: An off-white precipitate is formed.
Add some dilute H2SO4 (1 mol/l): The precipitate dissolves, the liquid becomes
colorless.
Add some dilute HCl (appr. 10 g/l): The liquid becomes yellow and clear.