Basic concepts of organic chemistry Flashcards
Organic compounds can be:
-Aliphatic - Contain carbon and hydrogen in straight, branched or non aromatic rings
-Alicyclic- An aliphatic compound arranged in non aromatic rings
-Saturated- Single bonds only
-Unsaturated- Contains double bonds
-Aromatic - A compound containing a benzene ring
Features of a homologous series
1) Same functional group
2) Each successive member differs by a CH2
3) Same general formula
4) Similar chemical properties
4) Trend in physical properties
General formula for alkanes
Cn H2n + 2
Homologous series
Alkanes - CnH2n+2
Cycloalkanes - CnH2n
Alkenes - CnH2n - Double bond
Aldehydes - C=O : carbonyl bond at the end of the chain
Ketones - Carbonyl group in the middle
Carboxylic Acids - C=O and OH at the end
Nitriles - Triple bond at the end of the chain
Amines - NH2
Naming organic compounds
1) The longest unbranched carbon chain in the molecule
2) Branched carbon chains - alkyl groups
CnH2n+1
CH3 - Methyl
CH2CH2 - Ethyl
3) Position of the functional group on a carbon chain
Number from the side that gives the lowest possible positional number
4) Multiple functional groups - put in alphabetical order
5) Id more than one of the same functional group is present use the prefixes di,tri,tetra,penta,hexa etc
Separate number with commas and speedster number and names with dashes
Naming Alcohols
Named by writing the position of the functional group before the suffix
e.g propan-2-ol
If there is more than 1 OH group in an alcohol, the position and number of groups is written in the middle of the name
In a diol, an e is added before the numbers
e.g ethane-1,2-diol
Naming alkenes
Named by writing the position of the functional group before the suffix
e.g but-2-ene
If there is more than one C=C in an alkene the position and the number of groups is written in the middle of the name before the functional group
e.g buta-1,3-diene
Naming aldehydes
Named by changing the suffix
They have the C=O functional group at the end of the carbon chain
Their name ends in -al
Naming ketones
Named by changing the suffix
They have the C=O functional group in the middle of the carbon chain
Their name ends in -one
When there are 5 or more carbons in a ketone, a number must be given for the position of the C=O as there is more than 1 position that it can go
Naming carboxylic acids
Named by changing the suffix
Have the carboxyl functional group at the end of the carbon chain
Their name ends in -oic acid
Naming amines
Amines have the NH2 functional group anywhere in the chain
Their name can start with amino or end in amine
Naming nitriles
Nitriles have the CN functional group at the end of the carbon chain Their name
Their name ends in nitrile
The CN bond is a triple bond
Where the CN bond is is counted as the first carbon in the chain
Isomerism
Structural isomerism - Same molecular formula but different structural formula
Stereoisomerism - Same structural formula but different arrangement in space
Structural Isomeridm
(Chain isomerism)
Molecules with the same molecular formula but a different length of carbon chain
Structural isomerism
(Position isomerism)
Molecules with the same molecular formula and same length of carbon chain BUT the functional group is attached at different positions along the chain
Structural isomerism
(Functional group isomerism)
Molecules with the same molecular formula but a different functional group
