Description of experiment
Below follows a plain text transcript of the selected experiment.
Needed compounds:
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acetone : CH3 CO CH3
citric acid : COOH CH2 COH(COOH) CH2 COOH
copper : Cu
nitric acid : HNO3
sulphuric acid : H2SO4
Class:
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elem=S;N
hydration
Summary:
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When concentrated sulphuric acid is added to concentrated nitric acid,
then some heating can be observed.
The mixed acid reacts with tissue, but not as strongly as pure sulphuric
acid does. The mixed acid reacts with copper, but this reaction is not
as strong as the reaction with nitric acid only.
With citric acid and acetone no strong reaction occurs.
Description:
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Add some concentrated sulphuric acid (96%) to the same volume of concentrated
nitric acid (appr. 65% by weight HNO3): The liquids mix with some production
of heat, but much less heat is produced, than when sulphuric acid and water
are mixed. The resulting liquid fumes when in contact with air.
Add some of the mix of H2SO4/HNO3 to a piece of paper tissue and let the
mixture soak into the tissue for several minutes: The tissue becomes
yellow/orange/brown.
Rinse the piece of tissue with water carefully and let dry. Light the dried
piece of tissue with a match: The tissue does not burn more vigorously than
normal tissue. After burning a black piece remains.
Add some of the mix of H2SO4/HNO3 to a copper coin: Smell of nitrous vapors
can be observed, but the typical brown color cannot be seen. There is no
vigorous reaction. The mixture does not bubble or foam (as it does when
only HNO3 was used).
Add some of the mix of H2SO4/HNO3 to some solid citric acid: No visible
reaction, some of the citric acid may dissolve, but this is hard to see.
Add some of the mix of H2SO4/HNO3 to some acetone: The acidic mixture
dissolves in the acetone. No visible reaction occurs.