Question

How do you name `"C"_5"H"_11"OH"` if it is a straight-chained alcohol?

Answer 1

Count the number of carbons to find that there are five. That means, from the prefixes you were taught, you can match up with one of the following:

• `"meth"-` = one carbon
• `"eth"-` = two carbons
• `"prop"-` = three carbons
• `"but"-` = four carbons
• `"pent"-` = five carbons
• `"hex"-` = six carbons

Since this is an alkane (the main chain contains only `"C"` and `"H"`, and no double or triple bonds. That is, the compound is completely saturated with hydrogen atoms), the middle of the name contains `-"an"-`.

So far we have `bb("pentan"-)`.

Then, you should note that `-"OH"` connected to a `-"CH"_2-` is called a hydroxyl group. Any hydrocarbon with a `-"CH"_3` (a terminal methyl group) replaced with a hydroxyl group is called an alcohol. Those end in the suffix `-"ol"`.

`=> "pent" + "an" + "ol" = [ . . . ]`

Therefore, this is called `bbcolor(blue)("pentanol")`.