The Alco test-tube contains mainly the sulphate of potassium dichromate (acidified with sulphuric acid), which is reduced to potassium sulphate and chromium sulphate:
Cr6+ + 3 e- → Cr3+
In a parallel test air could be pumped through water to show that ethanol is the reducing agent. In the context of this experiment the danger of "drinking and driving" could be discussed.
What you can learn about
- Alcohols can be oxidized by oxidizing agents.
- The presence of alcohol can be detected by the use of coloured oxidizing agents
- Easy teaching and efficient learning by using interactive experimentation PHYWE-Software
- Experiment is part of a complete solution set with experiments for the topic Organic Chemistry matched with international curriculum: all topics are covered