Alcohols

Can you name some different types of alcohol? Beer? Wine? Whiskey? Actually they all contain the same alcohol - ethanol.

Ethanol is only one member of the alcohol family. Members of the alcohol family are close relatives to another group of compounds... the alkanes. But with one important difference. Let's start with an alkane.

This is the smallest one, with only one carbon atom - methane. Now we'll make a small change to it. Remove one of the hydrogens... ... and replace it with this group ... an oxygen atom bonded to a hydrogen atom...

a hydroxy group, also known as a hydroxyl group. The methane has become methanol. The smallest alcohol. We can do this with any of the alkanes. Replace one hydrogen in this ethane with a hydroxy group and we get...

Ethanol... ... the alcohol used in alcoholic beverages. Propane becomes propanol. And so on. The names of the alkanes get an "ol" attached to them.

It's like a last name, showing that they all belong to the same family - alcohols. What are the uses of alcohols? Methanol, the smallest alcohol, is poisonous, even in tiny amounts. It can be used as a solvent, and as a cleaning agent. ... or as fuel for vehicles.

Ethanol is the most common alcohol. It is the only edible alcohol, but in larger amounts, it is harmful for us, especially to the liver and the brain. Just like methanol, it is also used as a solvent and as a cleaning agent. It also kills bacteria - so it's used in hand sanitizers And as a disinfectant in hospitals. Ethanol is also used as a fuel, often mixed with gasoline.

Propanol and butanol are used in products like nail polish and perfumes. Alcohol molecules may look similar to alkanes - there is just one atom that differs... ... but the hydroxy group results in different properties. The bonds between molecules are stronger in alcohols than in alkanes. This means that alcohols have much higher boiling points than alkanes of a similar size.

The first four alkanes are gases at room temperature. But even the smallest of the alcohols - methanol - is a liquid. The hydroxy group also makes the smaller alcohols water soluble. As the carbon chain gets longer, the solubility of an alcohol reduces. On the other hand, the longer the carbon chain gets, the more the alcohol molecule looks like an alkane.

And that makes these alcohols soluble in oil and other fat-soluble substances. The ability to dissolve fat and be water soluble, means that alcohols like ethanol and propanol are very useful as solvents and cleaning agents. So, there are many different types of alcohol, not only the kind you can drink. It is a class of substances with many different uses.