Draw a molecule and see what it is
Draw any organic structure and watch its molecular formula, molar mass, functional groups and, when it is known, its name appear as you draw. Have a name from your teacher or textbook? Draw it and compare.
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Example
3-methylbutan-2-one
C5H10O · 86.13 g/mol · ketone
How it works
Draw the structure
Drag from dot to dot to draw bonds, then tap a bond or an atom to change it. Hydrogens on carbon are implied, as in any skeletal formula.
See what you drew
The name, molecular formula, molar mass, functional groups and stereochemistry update as you draw. A structure that cannot exist, such as a carbon with five bonds, is pointed out.
Compare with your exercises
Check your drawing against the name your teacher or textbook gives. Names come from this site's checked exercises or from PubChem, whose names can differ in style from the ones your course uses.
Practise with feedback
Want exercises? In practice you read an IUPAC name, draw the molecule and get feedback that understands chemistry: equivalent drawings are accepted, and mistakes such as a missing carbon, the wrong functional group or a misplaced substituent are explained. Hints and a worked answer are there when you need them.
Topics
Alkanes and cycloalkanes
Parent chains, alkyl substituents, numbering and simple rings.
Alkenes and alkynes
Placing C=C and C≡C bonds with the -ene and -yne endings.
Haloalkanes
Fluoro, chloro, bromo and iodo substituents on carbon chains.
Alcohols and ethers
The -ol suffix, hydroxy groups and alkoxy substituents.
Aldehydes and ketones
The -al and -one suffixes and where the carbonyl group goes.
Carboxylic acids and derivatives
Carboxylic acids, esters, amides and acyl chlorides.
Amines and nitriles
Primary, secondary and tertiary amines, N-substituents and nitriles.
Benzene derivatives
Substituted benzenes, ring numbering and common parent names.
Stereochemistry: E/Z and R/S
Drawing double-bond geometry and stereocentres with wedge and hash bonds.
Why you can trust the checker
Answers are compared as molecules using RDKit, a widely used open-source chemistry toolkit. A correct structure is accepted however you draw it, and a different molecule is never accepted just because it has the same formula. Every exercise name has been checked against its structure with two independent sources before publication. Read the full grading rules.