Build hydrocarbon structures interactively and get IUPAC names automatically.
Hydrocarbons — compounds built purely from carbon and hydrogen — form the structural backbone of organic chemistry, and building them correctly by hand is the essential first skill before tackling reaction mechanisms or synthesis. This structure-building practice underlies AP Chemistry organic content and every subsequent IChO organic problem.
Alkanes (CnH2n+2) contain only single bonds and are named by identifying the longest continuous carbon chain, then numbering it to give substituents the lowest possible locants. Alkenes (CnH2n) contain at least one C=C double bond, introducing geometric isomerism: when each carbon of the double bond has two different substituents, cis/trans (or the more rigorous E/Z, based on CIP priority) isomers exist as genuinely different compounds with different physical properties, not just different drawings of the same molecule.
Alkynes (CnH2n-2) contain a C≡C triple bond and are named with the "-yne" suffix; because the triple bond is linear, alkynes cannot show cis/trans isomerism at that bond. Degree of unsaturation — calculated from molecular formula as DoU = (2C + 2 + N - H)/2 — tells you the total number of rings and pi bonds in a molecule before you even see its structure, a fast sanity check used throughout organic problem-solving.
Cyclic hydrocarbons introduce ring strain considerations: cyclopropane and cyclobutane have significant angle strain from forcing bond angles far from the ideal 109.5°, while cyclohexane can adopt a chair conformation with zero angle strain. Aromatic hydrocarbons, built on the benzene ring, follow Hückel's rule (4n+2 pi electrons) for aromatic stabilization and undergo substitution reactions rather than the addition reactions typical of alkenes.
This hydrocarbon builder lets you construct any structure by clicking to add carbons and bonds, automatically generates the correct IUPAC name, and displays structural, condensed, and bond-line formulas side by side — building the structural fluency that every later organic chemistry topic depends on.