Functional Group
A bond or an atom or a group of atoms that determine(s) the physical and chemical properties of a group of organic compounds.

  1. single bonds
  2. double bonds
  3. triple bonds
  4. haloalkane
  5. hydroxyl group
  6. carboxylic group
  7. ester group
  8. aldehyde group
  9. ketone group

organics compound consisting only of hydrogen and carbon atoms

Compounds in which there are no multiple bonds between C atoms in their hydrocarbon chains.
i.e. there are only single bonds between the carbon atoms

Compounds with one or more multiple bonds between C atoms in their hydrocarbon chains.
i.e. organics compound consisting of double or triple bonds between the carbon atoms.

General Formula
the general ratio of elements in a compound.
example: CnH2n+2
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Homologous Series
A series of organic compounds that can be described by the same general formula OR in which one member differs from the next with a CH2 group. Also called family, or class.


  1. alkanes
  2. alkenes
  3. alkynes
  4. halo-alkanes
  5. alcohols
  6. carboxylic acids
  7. esters
  8. aldehydes
  9. ketones

Molecular Formula
A chemical formula that indicates the type of atoms and the correct number of each atom in a molecule.
i.e. actual number of elements in a compound
example: C2H6

Empirical Formula
this is the simplest ratio of elements in a compound
molecular C2H6
empirical CH3.
The numbers were brought to the the smallest form by dividing by 2

Structural Formula
A structural formula of a compound shows which atoms are attached to which within the molecule. Atoms are represented by their chemical symbols and lines are used to represent ALL the bonds that hold the atoms together.

Condensed Formula
This notation shows the way in which atoms are bonded together in the molecule, but DOES NOT SHOW ALL bond lines.

Structural Isomers
(3 types)
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These are compounds that have the same molecular formula, but different structural formulae
If we say that TWO compounds are structural isomers, then they have exactly the same number and type of individual atoms, but are arranged into different structures.
Obviously they would have different names.

conjugated dienes: two double bonds separated by a single bond
isolated diens: one or more saturated carbons atoms between two double bonds
cumulated dienes: two double bonds formed to one carbon atom

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