Advice 1: How to determine ethanol

Ethyl alcohol is well known, it is included in all alcoholic beverages. The appearance of ethanol – clear, colorless liquid with a sharp characteristic odor, slightly lighter than water. There are cases of severe poisoning, when the ethanol take other organic liquids, including such toxic as methyl alcohol. A particular danger and deceit of methanol in the fact that the consumption of even small amounts of this alcoholand can cause blindness or death, and in appearance, smell, density and taste is almost indistinguishable from ethanol.
How to determine ethanol
Instruction
1
Suppose you have two cans, one with ethanol and the other methanol. How to distinguish the relatively harmless ethyl alcohol from methyl deadly? At home the most simple way is the following method. Pour a small amount of alcoholand some cans in a separate glass container: glass or jar. To avoid confusion, from which the canisters had been taken to test, make a note (e.g., a marker).
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Then take the copper wire, better fat. One end, wrapping it around a pencil or nail, coil. Another pinch pliers or an oven MITT, heat in a flame. As soon as the copper spiral is heated, as possible dip it in a glass or jar with the sample. Immediately you will hear the hiss, and you will feel strong smell.
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If the sample was a methanol smell is very pungent, unpleasant. The fact that there was a chemical reaction: CH3OH = SNO + H2. The result of this reaction formed the substance SNO – formaldehyde (formic aldehyde) with a sharp characteristic odor.
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If the sample contained ethanol, the smell will be much softer, nicer. It resembles the scent of rotten apples. Because the reaction C2H5OH = СН3СНО + H2, and formed acetaldehyde (or acetaldehyde).
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There is also a sensitive qualitative reaction for ethyl alcohol. It's called iodoform sample flows on such a scheme: C2H5OH + 6NaОН + 4I2 = CHI3 +HCOONa + 5NaI + H2O. The interaction of ethanol with an alkaline solution and iodine solution while cooling the reaction vessel is formed a light yellow suspension. Using iodoformi tests can detect ethanol, even at very low concentrations (of the order of 0.05%). If the concentration of alcoholand the high, the resulting slurry will quickly precipitate.

Advice 2: How to determine methyl alcohol

Methyl alcohol – a compound belonging to the group of Monohydric alcohols. Methanol is highly toxic, only 10 ml of this substance can cause severe Central nervous system damage, blindness, and 30 ml is death. Hence the need of identifying it. Much easier analysis of methyl alcohol to carry out in the Toxicological laboratory, but it is possible to make the simplest definition even at home.
How to determine methyl alcohol
Instruction
1
Methanol is a colorless, odor and taste not unlike ethanol. However, qualitatively, these substances vary considerably. In this regard, and for the majority of poisonings. If the test solution contains only one alcohol, to determine what, not working. But if you can see a mixture of alcohols or alcohol with impurities, to know the qualitative and quantitative content is possible only in laboratory conditions.

For determination of certain alcohols (ethanol, glycerol) there is a positive reaction – iodoform test. It is performed very first to confirm or exclude the content of ethanol in methanol. The result of the sample precipitate of bright yellow crystals triiodomethane (iodoform). Methanol this reaction does not.

C₂H₅OH + J₂ + NaOH = CHJ₃↓ + NaJ + HCOONa + H₂O
2
A qualitative reaction for methyl alcohol is based on its transformation into methyl aldehyde (formaldehyde). Pour the solution into a test tube with vapor tube, add potassium permanganate in presence of sulphuric acid. In the result of distillation to form formaldehyde, which can act in different reagents. The Schiff gives a strong violet staining hronotroponoe acid – violet color of the solution, potassium hexacyanoferrate – blue-violet staining reagent Felling – black precipitate. These reactions are certifying on methanol.
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At home research can be conducted by using a copper wire. Glow over a flame and immerse in the test solution. If it contained methanol, it will be the smell of formalin - the sharp and very unpleasant. With ethanol, this effect will be.

Quantitative determination of the content of methanol is carried out in the laboratory by titrimetric methods and by gas-liquid chromatography.
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