Question

What is the prefix for a -SH group?

		hydroxy-
		carboxy-
		oxo-
		acetyl-
		mercapto-

Answer 1

The International Union for Pure and Applied Chemistry (IUPAC) has established rules for organic chemical nomenclature.

In an IUPAC name, there are four parts:

Prefix–Parent–Infix–Suffix

The parent tells how many carbon atoms are in the main chain.

The infix tells the type of carbon-carbon bonding: for example -an- for alkanes, -en- for alkenes and -yn- for alkynes.

The suffix tells the family of the molecules, what is the highest-priority non-carbon functionality in the molecule.

The prefix lists all remaining substituents on the main chain, in alphabetical order.

Please find attached list for prefix and suffix depending on functional group

Thiols or -SH containing groups are traditionally called “mercaptans,” and you will sometimes see a
“mercapto” prefix for an SH group; this is now-superseded, by the IUPAC system of nomenclature.

So to answer your question prefix for a -SH group as per the choices given will be mercapto-