Description of experiment
Below follows a plain text transcript of the selected experiment.
Needed compounds:
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sulphuric acid : H2SO4
potassium dichromate : K2Cr2O7
metol : (CH3 NH C6H4 OH)2 . H2SO4
benzotriazole : C6H4 N3H
Class:
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elem=C
redox
Summary:
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Benztriazole cannot be oxidized by acidified dichromate. Metol is
quickly oxidized.
Description:
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Add some solid benztriazole to a solution of K2Cr2O7 in H2SO4 (appr. 5%
by weight): The benztriazole dissolves, no visible reaction, liquid
remains orange.
Add some metol: Liquid turns clear red/brown.
Add an excess amount of metol: Liquid turns darker and becomes brown.
Heat to appr. 60 C: Liquid turns dark purple and a strange odour comes
from the liquid (not comparable to the smell of anything from daily life).
The odour is not suffocating or irritating, nor is it extremely pleasant
or unpleasant.