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In the IUPAC system, the name of the alkane chain loses the terminal "e" and adds "ol", e.g. "methanol" and "ethanol". When necessary, the position of the hydroxyl group is indicated by a number between the alkane name and the "ol": propan-1-ol for CH3CH2CH2OH, propan-2-ol for CH3CH(OH)CH3. Sometimes, the position number is written before the IUPAC name: 1-propanol and 2-propanol. If a higher priority group is present (such as an aldehyde, ketone or carboxylic acid), then it is necessary to use the prefix "hydroxy", for example: 1-hydroxy-2-propanone (CH3COCH2OH).
Common names for alcohols usually takes name of the corresponding alkyl group and add the word "alcohol", e.g. methyl alcohol, ethyl alcohol or tert-butyl alcohol. Propyl alcohol may be n-propyl alcohol or isopropyl alcohol depending on whether the hydroxyl group is bonded to the 1st or 2nd carbon on the propane chain. Isopropyl alcohol is also occasionally called sec-propyl alcohol.
As mentioned above alcohols are classified as primary (1°), secondary (2°) or tertiary (3°), and common names often indicate this in the alkyl group prefix. For example (CH3)3COH is a tertiary alcohol is commonly known as tert-butyl alcohol. This would be named 2-methylpropan-2-ol under IUPAC rules, indicating a propane chain with methyl and hydroxyl groups both attached to the middle (#2) carbon.
The word "alcohol" almost certainly comes from the Arabic language (the "al-" prefix being the Arabic definite article); however, the precise origin is unclear. The Persian physician and scientist Rhazes discovered this substance, but because he wanted his book to be published in most of the then-known world, he used the Arabic language instead of Persian (although he made copies in Persian). The word was introduced into Europe, together with the art of distillation and the substance itself, around the 12th century by various European authors who translated and popularized the discoveries of Islamic and Persian alchemists.
A popular theory, found in many dictionaries, is that it comes from ????? al-kuh.l, originally the name of very finely powdered antimony sulfide Sb2S3 used as an antiseptic and eyeliner. The powder is prepared by sublimation of the natural mineral stibnite in a closed vessel. According to this theory, the meaning of alkuhul would have been first extended to distilled substances in general, and then narrowed to ethanol. This conjectured etymology has been circulating in England since 1672 at least (OED).
However, this derivation is suspicious since the current Arabic name for alcohol, ?????? al-kuh.u-l, does not derive from al-kuh.l. The Qur'an, in verse 37:47, uses the word ????? al-g.awl — properly meaning "spirit" or "demon" — with the sense "the thing that gives the wine its headiness". The word al-g.awl is also the origin of the English word "ghoul", and the name of the star Algol. This derivation would, of course, be consistent with the use of "spirit" or "spirit of wine" as synonymous of "alcohol" in most Western languages. (Incidentally, the etymology "alcohol" = "the devil" was used in the 1930s by the U.S. Temperance movement for propaganda purposes.)
According to the second theory, the popular etymology and the spelling "alcohol" would not be due to generalization of the meaning of al-kuh.l, but rather to Western alchemists and authors confusing the two words al-kuh.l and al-ghawl, which have indeed been transliterated in many different and overlapping ways.
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