Final answer:
In experiments involving potassium dichromate (VI) to identify organic compounds, the two possible results are the conversion of alcohols to carboxylic acids or aldehydes and a distinct color change from orange to green due to the reduction of chromium ions.
Step-by-step explanation:
When identifying organic compounds with acidified potassium dichromate (VI), there are two possible results you might observe, reflecting the oxidative capacity of the potassium dichromate. During such a reaction, if the organic compound is an alcohol, potassium dichromate serves as an oxidizing agent and can oxidize alcohols to carboxylic acids or aldehydes, depending on the type of alcohol and reaction conditions. The balanced chemical equation, demonstrating this oxidation shows how ethyl alcohol (CH₂CH₂OH) is oxidized to become acetaldehyde (CH₂CHO). The change in color from orange to green is characteristic of the reduction of Cr6+ in dichromate to Cr3+. In laboratory conditions, the presence of acid and the dichromate ion initiates the oxidation where the Cr₂O₇²- is reduced to Cr³+ as the alcohol is oxidized. This color change is a key indicator during the reaction. For example, when potassium dichromate (K₂Cr₂O₇) is mixed with ethanol in acidic conditions, the resulting mixture demonstrates a color change, due to the reduction of chromium ions in the dichromate, from their original orange color to a distinct green color as they form Cr³+ ions. This colorimetric change is often utilized in the Breathalyzer test to measure blood alcohol content by observing the change from yellow-orange (Cr₂O₇²-) to green (Cr³+) as a result of the ethanol oxidation.