Ethyl alcohol is often irreplaceable in life. When it is used for especially medical purposes – to wipe skin before an injection, to put cups or to make a spirit compress, – its quality can be and not too high. The impurity which are contained in alcohol will not do harm to health as they get into a human body in scanty quantities. However, if alcohol is used in house cookery, for example, for production of fruit liqueurs, tinctures, spirit extracts here the question of its quality becomes very important!
It is required to you
- - mirror;
- - potassium permanganate;
- - matches.
Instruction
1. Remember that ethyl alcohol of rather high extent of cleaning, evaporates from a smooth clean surface, without leaving any marks. The most suitable subject for this test – a mirror. It has to be completely cleaned from pollution, dust and traces of fat! For this purpose wash its surface with any degreasing component (simplest – with baking soda), then carefully rinse under a pure stream, wait for drying (without wiping with anything!).
2. Arrange a mirror horizontally and apply on a clean dry surface one – two drops of alcohol. After alcohol completely evaporates, consider a surface in "slanting light", that is sideways. If the smooth surface is absolutely clean, as a last resort, with hardly noticeable "stains", then alcohol can be considered rather clean. If stains are well noticeable, then in alcohol there are a lot of impurity.
3. And if near at hand there is no suitable pocket mirror, or there is no wish to spend time for quite long test? Not each person will have enough patience to wait until at first the washed-up mirror dries, and alcohol will evaporate then! In this case you can arrive and in a different way. Prepare small amount of weak (light pink) water solution of permanganate of potassium – KMnO4 and carefully flow it to alcohol (it is desirable in a proportion 1:3). The more in alcohol of foreign impurity, the quicker it will be painted in color of solution of "potassium permanganate". If quality alcohol, then coloring occurs not earlier, than in 5 minutes.
4. Absolutely simple and not really reliable test is as follows: pour a little alcohol in the flat capacity (the glass cup will approach Understand, as a last resort, a saucer) and set fire. The pure concentrated alcohol burns with quite strong blue flame. The more in it impurity, the more yellow shade will be in a flame.