formulas

• molecular formular:

  formula that gives the ACTUAL number of atoms of each element in one molecule
• Empirical Formula:


  gives the SIMPLEST RATIO of atoms of each element in a compound
• General Formula 


  shows the number of atoms of each element in a substance which has n carbon atoms ( all molecules in homologous series have same general formula )
• Structural Formula: 


  shows how the atoms are joined together in a molecule, e.g. CH3CH2OH
• Displayed formula

  shows all the bonds and atoms in a molecule ( H-C-C-H )
• skeletal formula

  uses lines to represent bonds, each point = carbon atom, H atoms not usually shown.
• Alkyne has…

  ….a triple bond
• alkanes have..

  ..single bonds
• alkanes have…

  …double carbon bonds
• Steps of finding the empirical formula:

  1. find number of moles in C and H
  2. divide each moles by smallest number of moles
  3. find ratio of moles
  4. smallest number = C, larger number = H
• steps to finding the molecular formula:

  1. find Mr of compound using imperial formula and add together
  2. divide the Mr given by the new Mr to find the multiple
  3. multiply each atom in the Ef by the multiple
  4. substitute into formula
• drawing saturated carbons as a displayed formula:

  • single bonds only
  • can be drawn like a shape (e.g. hexagon)
• Reaction mechanisms definition:

  explains what happens in a reaction by showing the movement of electrons
• double headed arrow =

  a pair of electrons
• single sided arrow =

  single electron
• Free radicals definition:

  • unpaired electrons
  • usually reactive
  • drawn with half an arrow head and a dot
• order of hydrocarbons:

  1 carbon- meth

  2 carbon- eth

  3 carbon- prop

  4 carbon- but

  5 carbon- pent

  6 carbon- hex

  7 carbon- hept
• what is the suffix for alkenes?

  -ene, e.g. ethene
• what is the suffix for alcohols?

  -ol, e.g. ethanol
• what are the prefixes for haloalkanes?

  • chloro
  • bromo
  • iodo
  • fluoro
• what is the suffix for aldehydes?

  -al, e.g. ethanal
• what is the suffix for ketones?

  -one, e.g. butanone
• what is the suffix for carboxylate acids?

  -anoic acid, e.g. ethanoic acid
• what is the suffix for nitriles?

  -nitrile, e.g. ethanenitrile
• what is the suffix for amines?

  -amine, e.g. propylamine