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Organic Chemistry (ATC)

A community-written study guide covering every topic on this event's official test plan. Sign in to contribute to a section.

1Describe electronegativity – structure and bonding

16% of exam

Organic chemistry studies carbon-based molecules.

  • Carbon forms four bonds, enabling complex structures.
  • Electronegativity creates polar and nonpolar bonds.
  • Hybridization (sp, sp², sp³) determines shape.
  • Bonding controls molecular properties.

2Describe chemical bonds, shapes and naming of compounds

16% of exam

Structure and naming describe organic molecules.

  • Molecules have predictable 3D shapes.
  • IUPAC nomenclature names compounds systematically.
  • Structural formulas show connectivity.
  • Isomers share a formula but differ in structure.

3Describe stereochemistry

4% of exam

Stereochemistry studies 3D arrangement of atoms.

  • Isomers have the same formula but different structure or arrangement.
  • Chirality produces non-superimposable mirror images (enantiomers).
  • Stereochemistry affects drug activity.
  • Cis/trans isomerism changes properties.

4Describe substitution and elimination reactions

6% of exam

Two key reaction types transform organic molecules.

  • Substitution replaces one group with another (SN1, SN2).
  • Elimination removes atoms to form a double bond (E1, E2).
  • Reaction path depends on the substrate and conditions.
  • These reactions build and modify molecules.

5Identify aromatic compounds and IUPAC names

12% of exam

Aromatic compounds contain stable ring structures.

  • Benzene is the classic aromatic ring.
  • Aromatic rings are unusually stable (resonance).
  • IUPAC rules name substituted rings.
  • Aromatics are common in drugs and biology.

6Differentiate and describe alkanes, alkenes, alkynes, cycloalkanes, alcohols, ethers, epoxides, sulfides, aldehydes, ketones, and functional groups

26% of exam

Functional groups define organic families.

  • Alkanes (single), alkenes (double), alkynes (triple bonds).
  • Alcohols (-OH), ethers, aldehydes, and ketones have oxygen groups.
  • Each functional group gives characteristic reactivity.
  • Recognizing groups predicts behavior.

7Identify carboxylic acids and derivatives

8% of exam

Carboxylic acids and their relatives are common in biology.

  • Carboxylic acids contain the -COOH group.
  • Derivatives include esters, amides, and anhydrides.
  • Esters give many fruits their smell.
  • These groups are key in fats, proteins, and drugs.

8Understanding how to name amines

8% of exam

Amines are nitrogen-containing organic compounds.

  • Amines contain nitrogen bonded to carbon.
  • Classified as primary, secondary, or tertiary.
  • They act as weak bases.
  • Amines are found in amino acids and many drugs.

9Describe spectroscopy

4% of exam

Spectroscopy identifies molecular structure.

  • IR spectroscopy identifies functional groups.
  • NMR reveals the carbon-hydrogen framework.
  • Mass spectrometry measures molecular weight.
  • These tools confirm structure and purity.

Member-written study notes, not official HOSA competition material. Topic titles and exam weights come from the official Organic Chemistry (ATC) guidelines.