Prefixes and suffixes of functional groups
The ending tells the class.
Reading a name
Chloropropane, propanol, propanal, propanone, propanoic acid, propene and propyne all have three carbon atoms. Their names differ at the start or at the end.
What do the different beginnings and endings tell us?
What this lesson covers
The idea
Haloalkanes take the prefix chloro- or bromo-; alcohols take the suffix -ol, aldehydes -al, ketones -one, carboxylic acids -oic acid, alkenes -ene and alkynes -yne.
Reading a name
Chloropropane, propanol, propanal, propanone, propanoic acid, propene and propyne all have three carbon atoms. Their names differ at the start or at the end.
What do the different beginnings and endings tell us?
- The functional group or bond in the compound
- The colour of the compound
- The temperature at which it melts
Match the class to its ending
Tap a class on the left, then its prefix or suffix on the right.
Prefix or suffix
Only the haloalkanes use a prefix. The other classes use a suffix, so the name of the chain stays in front.
Haloalkanes take the prefix chloro- or bromo-; alcohols take the suffix -ol, aldehydes -al, ketones -one, carboxylic acids -oic acid, alkenes -ene and alkynes -yne.
- Class | Prefix or suffix | Example
- Haloalkane | prefix chloro- or bromo- | chloropropane
- Alcohol | suffix -ol | propanol
- Aldehyde | suffix -al | propanal
- Ketone | suffix -one | propanone
- Carboxylic acid | suffix -oic acid | propanoic acid
- Alkene | suffix -ene | propene
- Alkyne | suffix -yne | propyne
Notes
Haloalkanes take the prefix chloro- or bromo-; alcohols the suffix -ol, aldehydes -al, ketones -one, carboxylic acids -oic acid, alkenes -ene and alkynes -yne.
Check yourself
Which name is that of the three-carbon alcohol?
Propanoic acid belongs to which class?
Which prefix is used for a chlorine atom that replaces a hydrogen atom?
The name propyne ends in -yne. What does this show?
- Propanal. The suffix -al marks an aldehyde.
- Propanone. The suffix -one marks a ketone.
- Propanol — correct. Yes!
- Carboxylic acids — correct. Yes!
- Aldehydes. Aldehydes take the suffix -al.
- Ketones. Ketones take the suffix -one.
- -ol. -ol is a suffix for alcohols.
- chloro- — correct. Yes!
- -ene. -ene is a suffix for alkenes, which have a double bond.
- A double bond between carbon atoms. A double bond is shown by the suffix -ene, as in propene.
- An -OH group. An -OH group is shown by the suffix -ol, as in propanol.
- A triple bond between carbon atoms — correct. Yes!