Ethanol - organic matter which belongs to the class of one-atomic alcohols. Under usual conditions it is colourless liquid, flying and combustible. Ethyl (or wine) alcohol is a part of vodka and many other alcoholic drinks. In addition it is used as fuel, as disinfectant in medicine and also is the main solvent in the perfumery industry.
It is required to you
- - test tubes;
- - heating device;
- - copper wire;
- - sodium hydroxide;
- - crystal iodine.
Instruction
1. There is a high-quality reaction to one-atomic alcohols which in their homological row quite a lot. Take a copper wire, curtail it on the end in the form of an eyelet or a spiralka and calcinate on a torch flame. As a result of oxidation reaction the wire will become covered by a black raid which represents copper oxide. Pour 2-3 ml of the studied substance in a test tube and lower in it the calcinated wire. You will be able to determine successful carrying out experience by characteristic signs. The wire will gain initial color and gloss of copper again, that is there will be its restoration from copper oxide. In addition there will be an unpleasant smell which demonstrates formation of acetic aldehyde. This reaction shows availability of one-atomic alcohol.
2. Besides there is also an opportunity to carry out the reactions capable to define specifically ethyl alcohol. For this purpose there is a yodoformny test. Take a test tube and place in it 1-2 kristallik of iodine. Add the studied substance, namely ethyl alcohol or ethanol in number of 1 ml. Carefully heat solution on a water bath then add 2 ml of sodium hydroxide. Leave the received mix for cooling. After a while there is an iodoform smell and also its allocation in the form of a suspension is observed. If concentration of alcohol initially was high, then the yellow deposit drops out. Characteristic signs can be shown not at once, and some hours or even day later.
3. However it is important to remember that this reaction has the errors as also some other studied substances can give a similar picture. Therefore it is desirable to carry out both reactions which supplement one another. Besides, ethyl alcohol usually well is determined by a characteristic smell of alcohol.