Description of experiment
Below follows a plain text transcript of the selected experiment.
Needed compounds:
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sodium chloride : NaCl
sulphuric acid : H2SO4
hydrochloric acid : HCl
potassium bromate : KBrO3
Class:
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elem=Br,Cl
redox
Summary:
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Bromate reacts with chlorides, releasing chlorine. Probably some bromine
is produced as well or a bromine/chlorine compound is produced.
Description:
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Sequence 1:
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Add some solid KBrO3 to some HCl (appr. 30% by weight): Vigorous evolution
of a green gas, liquid starts foaming. The liquid becomes slightly warmer.
When the reaction ceases, then the liquid is yellow and the gas mixture
above the liquid is green. A pungent smell of chlorine is present.
Sequence 2:
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Add some solid KBrO3 to some HCl (appr. 10% by weight): The solid dissolves,
while producing gas. The gas is produced at a nice constant rate, without
becoming vigorous. When the solid is dissolved, then the evolution of the
gas ceases. The gas mixture above the liquid is green and the liquid is
yellow.
Sequence 3:
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Add some solid KBrO3 to some dilute H2SO4 (appr. 2 mol/l): The solid dissolves,
albeit very slowly. The liquid becomes colorless.
Add some solid NaCl: The solid dissolves and there is a slow evolution of a
gas. The liquid becomes green and a strong smell of chlorine can be observed.