Question

Give the common name for this molecule. SH CH,CH.CH propanethiol propanethiol

Answer 1

The given molecule contains the 'thiol' functional group (-SH) which is also known as 'mercaptan'. Thus thiols are also called mercaptans. They are called so because the thiolate group ( RS^{​​​​​-} ) has the tendency to bind strongly to mercury compounds.

Since the compound contains 3 carbon atoms so the root word for the 3 membered carbon chain is 'prop' .

See the root words for different number of carbon atoms in chain

Number of carbon atoms	Root word
1	meth
2	eth
3	prop
4	but
5	pent
6	hex
7	hept
8	oct
9	non
10	dec

The IUPAC name of the molecule is 1-propanethiol whereas the common name of the molecule is propyl mercaptan. ( Propyl since the basic carbon chain is a hydrocarbon chain consisting of 3 carbon atoms and mercaptan is for the thiol functional group at position 1 in the chain )