Home / Learn / Chemistry / Isomer explorerTool #L51 (formerly #1106)

Isomer explorer: every structural isomer of C₄H₁₀, C₅H₁₂, C₄H₁₀O and more, named, with chain, position, functional and metamer isomerism

Pick a molecular formula (C₄H₁₀ to C₇H₁₆, C₄H₈, C₅H₁₀, C₂H₆O to C₅H₁₂O, C₃H₆O to C₅H₁₀O, C₂H₄O₂ to C₄H₈O₂) and see every open-chain structural isomer with its IUPAC name and condensed formula. Tap two to learn whether they are chain, position or functional isomers or metamers, spot cis–trans and chiral ones, and test yourself.

Keep it one tap away for everyday use.

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  1. Formula
  2. All isomers
  3. Tap two
  4. Check
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Pick a formula

    Kinds of structural isomers

    Chain
    Different carbon skeletonbutane and 2-methylpropane
    Position
    Same skeleton, group movedbutan-1-ol and butan-2-ol
    Functional
    Different familyethanol and methoxymethane
    Metamers
    Different groups each side of Oethoxyethane and 1-methoxypropane

    Try this

    • Step through C₄H₁₀, C₅H₁₂, C₆H₁₄ and C₇H₁₆: 2, 3, 5, 9 isomers. The number grows fast.
    • In C₄H₁₀O tap butan-1-ol and ethoxyethane, then ethoxyethane and 1-methoxypropane. What changes?
    • Find the isomers marked "cis and trans": each of them is really two compounds.
    • Find the ones marked "chiral carbon": each has a mirror-image twin (optical isomers).

    Check yourself

    New questions every time; nothing is saved.

    What it does

    Isomers have the same molecular formula but different structures. This page lists every open-chain structural isomer of a small formula, each with its IUPAC name and condensed structural formula (like CH₃–CH(OH)–CH₃). Tap any two and it tells you what kind of isomers they are:

    • Chain isomers: a different carbon skeleton (straight or branched).
    • Position isomers: the same skeleton, with the group or double bond in a different place.
    • Functional isomers: different families, such as an alcohol and an ether.
    • Metamers: ethers or esters with different carbon groups on the two sides of the oxygen.

    It also marks the isomers that come as cis and trans forms (geometric isomers) and those with a chiral carbon (optical isomers). It follows the Class 11 Chemistry chapter on organic chemistry basics (isomerism: structural and stereo) and the Class 10 idea that one formula can have more than one structure (butane and isobutane). Name your own structures with the IUPAC namer, check rings and double bonds with the unsaturation, and see how one isomer can still twist into many shapes with the newman projection spinner.

    How to use it

    1. Choose a Molecular formula. The list shows which families it covers.
    2. Read the count and the list. Each card shows the isomer number, name, condensed formula, family and any cis–trans or chiral mark.
    3. Tap two cards. The box above the list explains their relationship. Tap a card again to unpick it.
    4. Try Check yourself: two counting questions and two “what kind of isomers?” questions.

    Worked example: C₄H₁₀O

    The page finds 7 structural isomers: 4 alcohols (butan-1-ol, butan-2-ol, 2-methylpropan-1-ol, 2-methylpropan-2-ol) and 3 ethers (1-methoxypropane, 2-methoxypropane, ethoxyethane). Tap butan-1-ol and butan-2-ol: same skeleton, –OH moved, so position isomers. Butan-1-ol and 2-methylpropan-1-ol: chain isomers. Butan-1-ol and ethoxyethane: alcohol and ether, functional isomers. Ethoxyethane (2 + 2 carbons round the O) and 1-methoxypropane (3 + 1): metamers. Butan-2-ol is marked chiral: its carbon 2 holds H, OH, CH₃ and C₂H₅.

    Tips

    • Count carbon skeletons first. For C₅H₁₂O, there are 3 skeletons with 5 carbons; the –OH can go on 8 different carbons, and the O can sit in 6 different C–C bonds.
    • Same name twice means the same compound. Turning or flipping a drawing does not make a new isomer.
    • Esters are named alkyl alkanoate: “1-methylethyl methanoate” is also called propan-2-yl methanoate (isopropyl formate).

    FAQ

    Why are rings missing? The tool lists open chains only; the note under the count says which ring compounds share the formula.

    Is this an NCERT tool? No. It is a free fibub page made to help with this chapter; it runs on your device.

    Where the numbers come from

    • Isomer families and IUPAC names follow general organic chemistry teaching; structures are generated by fibub (every carbon tree, then every place for the double bond or oxygen), with duplicates removed by comparing canonical forms.
    • Checked against the well-known isomer counts: alkanes C₄ to C₇ have 2, 3, 5 and 9; open-chain C₄H₈ 3 and C₅H₁₀ 5; C₂H₆O to C₅H₁₂O 2, 3, 7 and 14; C₃H₆O to C₅H₁₀O (aldehydes and ketones) 2, 3 and 7; C₂H₄O₂ to C₄H₈O₂ (acids and esters) 2, 3 and 6; and every name against the standard IUPAC name of that compound.

    Standard scientific values, such as constants, atomic weights and melting points, are facts found in every textbook; we name where ours were checked. If you are an author or publisher and want a value, a credit or a table changed or removed, tell us and we will act quickly.

    Last updated 2026-11-09.

    Change log for Isomer explorer

    1. Add #1106 Isomer explorer Details on GitHub

    Every change to fibub

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