Archive for category Organic Chemistry

Carbon Chains

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  1. Organic Chemistry is Carbon Chemistry, Molecules made of chains or rings of carbon
  2. Organic molecules are commonly represented using a chemical formula, a structural formula or a condensed structural formula. These three forms are equivalent.
  3. The Structural Formula is referred to as the Fisher Structure in gamsat.

Aliphatics and Alkanes

  1. Meth = 1
  2. Eth = 2
  3. Prop = 3
  4. But = 4
  5. Penta = 5

Simple molecules like this are called Alkanes.

Representing Branches

Side chains can be represented using formulae like 2 ethyl butane or 2,4 diethyl pentane.

Models and Bonding

Alkenes

  1. Hydrocarbons with carbon double bonds are called Alkenes
  2. Alkenes are unsaturated as they are not maxed out with hydrogen molecules.
  3. Examples of Alkenes are Propene or Butene

Alkynes

  1. Alkynes have a triple bond
  2. Examples of Alkynes are Butyne or Propyne

Cyclical Compounds and Halides

  1. Cyclic Aliphatics are ring chemicals
  2. Examples are Cyclobutane or Methyl Cyclopentane

Benzene

  1. Benzene molecules are rings with alternating double bonds.
  2. Sometimes called aromatics because they tend to smell.
  3. f a benzene ring acs as a branch it’s a phenyl, eg. phenyl butane or 2-methy 3-phenyl butane

Alcohols

  1. Alcohols contain an OH group.
  2. This usually makes them polar creating strong intramolecular hydrogen bonds so they have much higher melting and boiling points.
  3. A Primary Alcohol has the OH group at the end of the molecule.
  4. A Secondary Alcohol has the OH chain as a branch. The carbons either side are often referred to as R for Rest.
  5. A Tertiary Alcohol is a secondary alcohol which has another group attached to the same carbon as the OH.

Carboxylic Acids

  1. Carboxylic acids have the Carboxylic acid functional group at the end
  2. End in -oic acid, eg Methanoic Acid.
  3. Methanoic Acid is otherwise known as Formic Acid
  4. Ethanoic Acid is otherwise known as Acetic Acid

Esters

  1. Made from Acohols and carboxylic acids
  2. eg Ethyl Methanoate

Ketones, Aldehydes, Ethers and Amines

  1. An Aldehyde has a double bonded Oxygen at the end of the Carbon chain
  2. Ketones have a double bonded Oxygen side group at a position other than the end of the carbon chain.
  3. Ketones have -one at the end of them, eg Butanone
  4. Ethers have an Oxygen in the middle of the carbon chain, eg Methyethylether
  5. An Amine has an NH2 side group. Eg. Amino Ethane.

Organic Chemistry Song

Naming Simple Organic Compounds

Fischer and Haworth Projections

Note the following molecular diagrams are NOT equivalent.

Fischer projections

  1. Generaly represent all the atoms
  2. use lines to represent bonds

eg.

D-glucose_Fischer

see http://en.wikipedia.org/wiki/Haworth_projection for more.

Haworth Projections

  1. Visualise the molecule in three dimentions so more commonly used for ring molecules.
  2. Carbon and Hydrogen atoms are assumed and are not drawn

eg

Glucose_Haworth

See http://en.wikipedia.org/wiki/Haworth_projection for more detail.

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Substitution reactions

  1. Substitution reactions happen in Alkanes and Benzene rings.
  2. They occur when a hydrogen atom is replaced by another atom or group.

Electrophilic Addition Reactions

Electrophilic reactions occur when a polar molecule attacks a double bond in a carbon chain.