C
Chemical Name Builder
How chemicals are “formed” in naming: prefixes, roots, suffixes
Build a name

Names like methyl aren’t magic — they’re parts.

Organic chemistry names are built from letter sequences: a root (chain length), optional prefixes (substituents like methyl-), and a suffix (functional group like -ol, -one).

🧱 Root: meth, eth, prop ➕ Prefix: methyl-, chloro-, di- 🏷️ Suffix: -ane, -ene, -ol, -oic acid

Note: This is an educational overview, not a full IUPAC engine.

A name is often shaped like:
prefix(es) + root + suffix
Example: 2-methyl + prop + an-1-ol2-methylpropan-1-ol
Root
How many carbons in the main chain.
Suffix
Which “main” functional group you have.
Prefix
Extra groups attached (methyl-, chloro-, etc.).
Locants
Numbers showing where things attach (2-, 3-, 1-).

How chemical names are “formed”

Think of naming as choosing a main chain, then describing what’s attached and what functional group dominates.

1) Pick the main chain (root)

The root hints carbon count: meth(1), eth(2), prop(3), but(4)…

Ex: prop + -ane → propane (3-carbon saturated chain)
2) Choose the “ending” (suffix)

Suffix tells the key functional group: -ane alkane, -ene alkene, -yne alkyne, -ol alcohol, -one ketone, -al aldehyde, -oic acid carboxylic acid.

Ex: eth + -anol → ethanol (2-carbon alcohol)
3) Add prefixes (substituents)

Prefixes describe attachments: methyl- (-CH₃), ethyl- (-C₂H₅), chloro- (-Cl), plus counts like di-, tri-.

Ex: 2-methyl + propane → 2-methylpropane
Rule of thumb

The main functional group usually “wins” the suffix, and substituents become prefixes. Numbers (locants) show positions: 2-methyl… means the methyl group is attached at carbon 2.

Build a name

Pick a root, suffix, and optional prefixes. We’ll generate a plausible example name.

Not all names need a locant (we’ll use it when it makes sense).

Generated name
methylpropane

Cheat sheet: common parts

These are the “name blocks” you’ll see constantly.

Roots (chain length)
meth- 1
eth- 2
prop- 3
but- 4
pent- 5
hex- 6
hept- 7
oct- 8
non- 9
dec- 10
Suffixes (functional groups)
-ane saturated hydrocarbon (alkane)
-ene double bond (alkene)
-yne triple bond (alkyne)
-ol alcohol (–OH)
-one ketone (C=O inside chain)
-al aldehyde (C=O at end)
-oic acid carboxylic acid (–COOH)
-amine amine (–NH₂ / substituted)
-nitrile nitrile (–C≡N)
Very common prefixes
methyl- –CH₃
ethyl- –C₂H₅
propyl- –C₃H₇
fluoro- –F
chloro- –Cl
bromo- –Br
iodo- –I
nitro- –NO₂

Multipliers: di- (2), tri- (3), tetra- (4). In full naming, ordering rules apply (alphabetical ignoring di/tri).

Examples you’ll recognize

A few “read it like LEGO” examples.

Ethanol
eth + an + ol
Alcohol
  • eth-: 2 carbons
  • -an-: single bonds
  • -ol: has an –OH group
Propanone (acetone)
prop + an + one
Ketone
  • prop-: 3 carbons
  • -one: ketone (C=O within chain)
2-methylpropane
methyl + prop + ane
Alkane
  • propane: 3-carbon saturated chain
  • 2-methyl: CH₃ attached at carbon 2
Propanoic acid
prop + an + oic acid
Carboxylic acid
  • prop-: 3 carbons
  • -oic acid: carboxylic acid group (–COOH)
Want it to go deeper?

Real IUPAC naming includes choosing the longest chain, prioritizing functional groups, using multiple locants, sorting substituents alphabetically, and handling rings (cyclo-), aromatics (benzene), and stereochemistry (E/Z, R/S).