SCH4U - Chemistry 12 (2024-25) - A

Summary

Alkanes

• • Unsaturated hydrocarbons
  • First part of name identifies number of carbons (meth-, eth-, prop-, but-, pent-, hex-, hept-, oct-, non-, dec-)
  • Have the suffix -ane
  • Alkyl groups are chains that branch off of root chains, these have the suffix -yl

Alcohols

• • Alcohols, which are organic compounds with hydroxyl groups, end with the suffix -ol
  • If there is more than one -OH group on the molecule, the suffix becomes -diol, -triol, etc.
  • In alcohols, the parent chain is numbered so that the -OH group is on the lowest numbered carbon

Ethers

• • Ethers are organic compounds with an oxygen atom bonded to 2 alkyl groups
  • The longer of the 2 alkyl groups bound to the oxygen atom is used to form the root name, using the full alkane name for that alkyl group (e.g. propyl becomes propane)
  • The suffix -oxy is added to the shorter of the 2 alkyl groups and this name comes in front of the root name (e.g. ethane becomes ethoxy)

Aldehydes

• • Aldehydes are organic compounds with carbonyl (-C=O) groups at the terminal end of a molecule
  • When naming aldehydes, the -e at the end of the root chain alkane name is replaced with -al

Ketones

• • Ketones are organic compounds with carbonyl groups in the middle of the molecule
  • When naming ketones, the -e at the end of the root chain alkane name is replaced with -one

Carboxylic Acids

• • Carboxylic acids are organic compounds with carboxyl groups at the terminal end of the molecule
  • When naming carboxylic acids, the -e at the end of the root chain alkane name is replaced with -oic acid

Amines

• • Amines are organic compounds that are derived from ammonia in which a nitrogen atom is bonded to one or more alkyl groups
  • Amines are classified as primary (1), secondary (2) or tertiary (3), depending on the number of alkyl groups they are bound to
  • Primary amines have the suffix -amine added to the name of the alkyl groups alkane name (e.g. propanamine)
  • Secondary amines have the root name of the longest alkyl group with the suffix -amine added. The shorter alkyl group is identified using the letter N-, if both alkyl groups are the same length, one is used as the root name and the other as the first name
  • Tertiary amines take the root name of the longest alkyl group, the other two are each identified by N-, if 2 of the 3 groups are the same, the are identified as N,N-di-

Naming Priority 

When there are more than 1 functional group present on an organic compound, a priority scale must be applied when numbering the carbons for naming:

Here are some examples: