Structural Formula Builder

Study displayed structural formulas for Cambridge IGCSE organic molecules — every atom and bond shown explicitly. Use Name It to identify formulas by name, or Spot It to find the correct formula for a given name.

Alkane1 of 15

methane

CH₄

Simplest hydrocarbon. One central carbon with four single C–H bonds. Tetrahedral in 3D (109.5°). Main component of natural gas.

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Functional Group Quick Reference

Memorise these groups — examiners always ask you to identify or draw them. Red = O · Blue = H · Grey = C

Alkane

C–C only

No functional group. All single bonds. General: CₙH₂ₙ₊₂

Alkene

C=C

Carbon–carbon double bond. General: CₙH₂ₙ. Unsaturated.

Alcohol

–OH

Hydroxyl group. Suffix: -ol. e.g. eth-an-ol

Carboxylic acid

–COOH

Carboxyl group: C=O and O–H on same carbon. Suffix: -anoic acid

Ester

–COO–

C=O with O linking two carbon chains. Suffix: -yl -anoate

IUPAC Carbon Chain Prefixes

1 C

meth-

2 C

eth-

3 C

prop-

4 C

but-

5 C

pent-

6 C

hex-

Combine prefix + suffix: eth + -anol = ethanol · prop + -anoic acid = propanoic acid