Organic nomenclature practice

Exercises for naming organic compounds, sorted by compound family. Each family has a short summary of its naming rules, 145 exercises in all to draw from the name, structures to name and a printable worksheet with an answer key.

Compound families

The order follows most courses: alkanes first, because every other family reuses their chain names and numbering rules, then one functional group at a time.

Alkanes and cycloalkanes
Parent chains, alkyl substituents, numbering and simple rings.
18 exercises to draw · 18 structures to name
Alkenes and alkynes
Placing C=C and C≡C bonds with the -ene and -yne endings.
18 exercises to draw · 18 structures to name
Haloalkanes
Fluoro, chloro, bromo and iodo substituents on carbon chains.
17 exercises to draw · 17 structures to name
Alcohols and ethers
The -ol suffix, hydroxy groups and alkoxy substituents.
18 exercises to draw · 18 structures to name
Aldehydes and ketones
The -al and -one suffixes and where the carbonyl group goes.
19 exercises to draw · 19 structures to name
Carboxylic acids and derivatives
Carboxylic acids, esters, amides and acyl chlorides.
19 exercises to draw · 19 structures to name
Amines and nitriles
Primary, secondary and tertiary amines, N-substituents and nitriles.
17 exercises to draw · 17 structures to name
Benzene derivatives
Substituted benzenes, ring numbering and common parent names.
19 exercises to draw · 19 structures to name

Two ways to practice

From the name to the structure. You read a name and draw the skeletal structure; the checker compares molecules, so any correct drawing is accepted. Start on the practice page or with a family above.
From the structure to the name. You see a structure and choose its name from four; every wrong choice is explained. Try Name the structure.

How a systematic name is built

Find the most important functional group: it becomes the suffix (-ol, -al, -one, -oic acid…). Everything else becomes a prefix.
Choose the parent chain or ring that contains that group, then the longest one.
Number the parent so that the suffix, then the multiple bonds, then the prefixes get the lowest locants.
Write the prefixes in alphabetical order, each with its locant, in front of the parent name.

The summary of the IUPAC naming rules explains each step with examples, and includes the table of functional group priority.

Skeletal and condensed formulas

On this site you draw skeletal structures: every corner and line end is a carbon, and the hydrogens on carbon are left out. Many courses also use condensed formulas such as CH₃–CH₂–OH. Both describe the same molecule, and in these families the worked answer of every compound without a ring also shows its condensed formula. Reading and drawing skeletal structures shows how to switch between the two.

For teachers

Every family has a printable worksheet with an answer key, and each topic has a link you can share with your class. See the page for teachers.