Naming Organic Compounds and the Formulas That Show Structure · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Naming organic molecules piece by piece

Science · Chemistry · ages 16-17
Name ______________________   Date ____________

  1. What is the name of CH3CH(CH3)CH2CH3?

    • 2-methylbutane
    • 3-methylbutane
    • 2-ethylpropane

  2. In an organic name, what does the stem tell you?

    • The main functional group
    • The length of the longest carbon chain
    • The number of branches

  3. What is the name of CH3CH(OH)CH2CH3?

    • Butan-3-ol
    • Butan-1-ol
    • Butan-2-ol

  4. You meet an unfamiliar molecule with a C-Br bond and no -OH. Which family is it?

    • Alcohol
    • Ketone
    • Haloalkane

  5. Which formula style draws every bond and atom?

    • Molecular
    • Skeletal
    • Displayed

  6. What does the general formula of a homologous series let you do?

    • Predict the next member before anyone makes it
    • Skip numbering the chain
    • Merge two families into one

  7. A student collapses a displayed formula to skeletal by keeping all the C-H bonds drawn. What is the error?

    • Skeletal should erase C-H bonds and let the zigzag speak
    • Skeletal should add extra carbons at each kink
    • Displayed formulas cannot be collapsed at all

  8. A skeletal zigzag is a line of four segments in a row. How many carbons does it hold?

    • Three
    • Six
    • Five
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Naming organic molecules piece by piece W1-mt_LCqg41gslT-s1

  1. 2-methylbutane · The four-carbon chain with a branch numbered lowest gives 2-methylbutane.
  2. The length of the longest carbon chain · The stem counts the longest chain: meth, eth, prop, but.
  3. Butan-2-ol · The hydroxyl gets the lowest number and -ol replaces -e.
  4. Haloalkane · A carbon-halogen bond marks a haloalkane.
  5. Displayed · Displayed shows every bond, slow but unambiguous.
  6. Predict the next member before anyone makes it · Each member adds one CH2, so properties shift gradually and predictably.
  7. Skeletal should erase C-H bonds and let the zigzag speak · Skeletal hides C-H bonds with carbons implied at kinks and ends.
  8. Five · Each segment end carries a carbon, and four segments in a row have five ends.
Worksheet · LightMySky