how are organic compounds categorised and synthesised?

allotrope

different physical forms in which an element can exist

valence electrons of carbon

• 4 valence electrons available for bonding (covalent)

stability of carbon bonds

• stable, low energy compounds when valence shells (2,8)

bond strength of carbons

• relatively stong

bond energy

energy required to break bonds in a molecule to individual atoms

• shorter bond length, more bond energy required

• strength of covalent bond is indicated by bond energy

bond length

distance between two nuclei

degree of unsaturation

• measured by reacting with iodine to identify iodine number

• higher number, higher amount of double bonds

iodine number

mass of iodine that reacts with 100g of a compound

aliphatic

organic compound in which carbon atoms form open chain

alkanes

• single bonds

• saturated

• C_nH_2n+2

• -ane

alkenes

• at least a double bond

• unsaturated

• C_nH_2n

• -ene

alkynes

• at least a triple bond

• unsaturated

• C_nH_2n-2

• -yne

cyclic hydrocarbons

• carbon chain is closed

• cyclo-

arenes

benzene (C₆H₆) - based hydrocarbons

alkyl

hydrocarbon chain that comes off the largest carbon chain

• -yl

functional groups

atom or group of atoms attached to a hydrocarbon chain & influences physical & chemical properties

• haloalkanes

• amines

• amides

haloalkanes

• hydrocarbon with one or more halogen attatched to carbon chain

• R-X

• -o

amines

• weak bases

• R-NH₂ (primary)

• amino-

• -amine

amides

• R-CONH₂ (carbonyl)

• -amide

alcohols

• R-OH

• hydroxy-

• -ol

primary (1°) alcohol

C-OH attatched to one other carbon

secondary (2°) alcohol

C-OH attatched to two other carbons

tertiary (3°) alcohol

C-OH attatched to three other carbons

aldehydes

• R-CHO (carbonyl)

• oxo-

• -al

ketones

• R-CO-R (carbonyl)

• oxo-

• -one

carboxylic acids

• weak acids

• R-COOH (carbonyl)

• -oic acid

ester

• R-COO-R (carbonyl)

• alkyl part from alcohol-

• -oate (from carboxylic acid)

priority for naming (highest-lowest)

1. carboxyl

2. ester

3. aldehyde

4. carbonyl

5. hydroxyl

6. amine

7. alkyne/alkene

8. alkane

structural isomers

molecules with same molecular formula but different structural formula

• chain isomers

• positional isomers

• functional isomers

chain isomers

difference in parent chain & alkyl branches

positional isomers

difference in location of functional group

functional isomers

difference in functional groups

intermolecular forces (IMF)

forces between molecules

• dispersion forces

• dipole-dipole

• hydrogen bonding

physical properties

• boiling & melting point (BP/MP)

• viscosity

• solubility

boiling & melting point (BP/MP)

• ↑ IMF, ↑ BP/MP

• ↓ branching, ↑ BP/MP

viscosity

resistance to flow of a liquid

• ↑ IMF, ↑ viscosity

solubility

• substance must be able to interact with water molecules (like-disolves-like)

• molecules that can form hydrogen bonds, ↑ solubility

• ↑ size, ↑ non-polar section, ↓ solubility

substitution reactions

reaction where one or more atoms of a molecule are replaced by different atoms

alkanes → primary haloalkanes

• alkane → _{UV light} primary haloalkane

• substitution reaction

primary haloalkane → primary alcohol

• primary haloalkane → primary alcohol

• substitution reaction

alkane → primary alcohol

• alkane → _{UV light} primary haloalkane

• seperate primary haloalkane using fractional distillation

• primary haloalkane → primary alcohol

addition reactions

reaction where one molecule bonds covalently with another molecule without loosing any other atoms

alkene → alkane

• alkene → _(catalyst) alkane

• addition reaction

primary alcohol → carboxylic acid

• primary alcohol → _{oxidising agent} aldehyde → _{oxiding agent} carboxylic acid

• oxidation reaction

secondary alcohol → ketone

• secondary alcohol → _{oxidising agent} ketone

• oxidation reaction

alkane → amine

• alkane → _{UV light} primary haloalkane → _heat amine

alkene → amine

• alkene → _catalyst alkane → _{UV light} primary haloalkane → _heat amine

alkane → carboxylic acid

• alkane → _{UV light} primary haloalkane → primary alcohol → carboxylic acid → (ester)

alkene → primary alcohol

• alkene → _{steam/H₃PO₄} primary alcohol