During the course of the experiment I wrote down a few observations including smells, colours etc. Below are the observations for the experiment in the order of observing them. 1. At the very beginning when I added the concentrated sulphuric acid to the water I noticed as I held the pear shaped flask that it began to heat up. This meant that the reaction between the acid and the water was an exothermic one meaning it gave out heat to the surroundings as energy was released.
The next step involved mixing of the sodium dichromate, which was a bright orange solid, and the water with the ethanol, which was a clear solution. The reason for this was because the reaction between the two solutions caused it to continue boiling. The resulting solution was a bright orange colour due to the sodium dichromate. 3. The concentrated sulphuric acid and water solution only needed a small blue flame under it for a short period before it began to boil rather vigorously. At this time I began to gradually add the orange solution so as to maintain the boiling of the ethanol and water solution.
As soon as the orange solution mixed with the sodium dichromate & water solution it turned a dark green. The colour of my distillate was not colourless, but very light yellow. 4. During the first test universal indicator was added to the distillate. This resulted in a very bright red solution, means that the distillate is a strong acid (a 1-2 on the pH scale). 5. During the second test, 2, 4-dinitrophenylhydrazine was added to the distillate. The mixture turned orange with a precipitate. Rohan Malhotra The Oxidation of ethanol AS – Assessed Practical (Skill I)