Chemistry · Grades 10–12
Aldehydes and ketones
Read the groups attached to the carbonyl carbon.
Learn the idea
Aldehyde
An aldehyde carbonyl carbon is bonded to at least one hydrogen.
Ketone
A ketone carbonyl carbon is bonded to two carbon groups.
Names
For simple school examples, -al indicates an aldehyde and -one a ketone.
Polarity
The carbonyl bond is polar, but behavior must be considered in the whole molecular context.
Worked examples
CH₃CHO belongs to which class?
The terminal carbonyl carbon is bonded to hydrogen.
Aldehydes.
CH₃COCH₃ belongs to which class?
The carbonyl carbon is attached to two carbon groups.
Ketones.
Check your understanding
What is the simple systematic name of CH₃CHO?
What is the simple systematic name of CH₃COCH₃?
How many carbon atoms are in CH₃COCH₂CH₃?
Answers and marking notes
Answers and marking notes
- ethanal
It is a two-carbon aldehyde.
- propanone
It is a three-carbon ketone.
- 4
Count the first methyl, carbonyl carbon, methylene and final methyl.
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Independent educational review required. Grade bands are approximate; these are not officially aligned curricula.