Description of experiment
Below follows a plain text transcript of the selected experiment.
Needed compounds:
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silver nitrate : AgNO3
nitric acid : HNO3
oxone : K2SO4.KHSO4.2KHSO5
sodium persulfate : Na2S2O8
Class:
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elem=O,S,Ag
redox
Summary:
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Peroxodisulfate ion gives a deep brown complex with silver ions in nitric acid.
Oxone (peroxomonosulfate) does not give such a complex, actually, it quickly
destroys such a complex.
Description:
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Dissolve some silver nitrate in appr. 50% nitric acid: The solid dissolves, but
some heating is required. The solid only dissolves with difficulty.
Cool down the solution under a running cold water tap.
Split the solution in two equal parts in two separate test tubes.
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To the first test tube add a small amount of sodium peroxodisulfate: The solid
dissolves partially. The liquid slowly turns dark brown. This is a nitrato
complex of silver(III).
To the brown liquid add a small amount of oxone: This solid also dissolves
partially. The brown color almost instantly disappears. The liquid becomes
colorless and a small amount of colorless gas is produced. This colorless gas
is oxygen.
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To the second test tube add a small amount of oxone: The solid partially
dissolves. The liquid remains colorless.
To this colorless liquid, add a somewhat larger amount of sodium
peroxodisulfate: The solid partially dissolves, the liquid remains colorless.