What, in scientific terms, is an alcohol? What’s the difference between, for example, sugar alcohols and the alcohol in whiskey?

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What, in scientific terms, is an alcohol? What’s the difference between, for example, sugar alcohols and the alcohol in whiskey?

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An alcohol is just an organic compound with an OH group which is bonded to a carbon atom. The carbon shouldn’t have any lone pairs or double bonds.

An alcohol is an organic compound made up of Carbon, Hidrogen and Oxygen, where an hydroxyl group (OH) is bound to a carbon of a chain. They’re polar compounds due to the oxygen presence, meaning they dissolve well in water and other compounds of polar nature.

The difference between a sugar alcohol(I suppose you’re just refering to sugar OH groups) and the one in a drink is the complexity of the Carbon chain. Alcohol in drinks is ethanol, but the taste comes from other compounds in the drink. Sugars are complex hydrocarbons with 4 or more carbons and OH groups.

Strictly speaking, in chemistry an alcohol is any organic molecule (i.e. a molecule based on a backbone of carbon atoms) that contains at least one *hydroxyl group*: a hydrogen atom bonded to an oxygen atom. There are lots of different alcohols. There is one important one that chemists call *ethanol*. Its chemical formula is C2H5OH. Two carbon atoms, one oxygen, and six hydrogens. So why don’t we write it as C2H6O? Well, you can, but chemists typically put the sixth hydrogen at the end with the oxygen, because it is part of the hydroxyl group I mentioned earlier, and that particular part of the molecule determines a lot of its chemical properties.

Why is ethanol important? Because this is the alcohol that is in drinks that we commonly call “alcoholic”, like wine, beer, whiskey, etc. So in common speech, “alcohol” means ethanol.

Sugar alcohols are alcohols that are made by *hydrogenating* sugar molecules. Hydrogenation basically means “sticking more hydrogen atoms onto it”. Sugar alcohols are quite different from the types of alcohol that ethanol belongs to. For one thing, they are solid at room temperature (like sugar is). Also, you can’t produce sugar alcohols through fermentation. And, obviously, sugar alcohols don’t have the intoxicating effects that ethanol does. In fact, sugar alcohols are often hard to digest, which can lead to problems like bloating, diarrhea or flatulence, if you eat too much of them (or if you are especially sensitive). Some sugar alcohols are even prescribed (in large doses) as laxatives.