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

• determined by bond length

• difference in electronegativity

• size of atoms

bond length

distance between two nuclei

degree of unsaturation

• iodine number

• molecular formula of DOU

• counting number of double/triple bonds

molecular formula of DOU

(2C + 2 + N - H - X) / 2

counting number of double/triple bonds

• cyclic = 1

iodine number

mass of iodine that reacts with 100g of a compound

• higher number, higher amount of double bonds

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

• hydrocarbon with one or more halogen attatched to carbon chain

• R-X

• -o

amines

• weak bases

• R-NH₂ (primary)

• amino-

• -amine

amides

• R-CONH₂

• -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

• -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 → _OH- primary alcohol

• substitution reaction

alkane → primary alcohol

• alkane → _{UV light} primary haloalkane

• seperate primary haloalkane using fractional distillation

• primary haloalkane → _OH- primary alcohol

addition reactions

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

alkene → alkane

• alkene → _(pt/pd/ni) alkane

• addition reaction

primary alcohol → carboxylic acid

• primary alcohol → _{oxidising agent (}K₂Cr₂O_{7) (low temp)} aldehyde → _{oxiding agent (}K₂Cr₂O_{7) (high temp)} carboxylic acid

• oxidation reaction

secondary alcohol → ketone

• secondary alcohol → _{oxidising agent (}K₂Cr₂O₇₎ ketone

• oxidation reaction

alkane → amine

• alkane → _{UV light} primary haloalkane + NH₃→ amine

alkene → amine

• alkene + H₂ → alkane → _{UV light} primary haloalkane + NH₃ → amine

alkane → carboxylic acid

• alkane → _{UV light} primary haloalkane → primary alcohol → _{oxidising agent (}K₂Cr₂O₇₎ carboxylic acid

alkene → primary alcohol

• alkene + H₂O → _{H₃PO₄ (high temp)} primary alcohol

condensation reactions

reaction where molecules react and link together by covalent bonding with elimination of a small molecule (ie. water) from the bond that is formed

• larger molecule synthesised from smaller molecules

• water is released

• new covalent bonds formed

• esterification

esterification

alcohol + carboxylic acid → _{concentrated acid (l)} ester + water

hydrolytic reactions

chemical breakdown of a compound due to a reaction with water

• larger molecule broken into smaller molecules

• water is added

• covalent bonds are broken

• hydrolysis

hydrolysis

ester + water → _{dilute acid (aq)} carboxylic acid + alcohol

proteins

large molecules composed of one or more long chains of amino acids

• polypetides

polypetides

condensation polymers made up of amino acid monomers

enzymes

protein that acts as a biological catalyst

• specific enzymes required for hydrolytic & condensation reactions in the body

hydrolytic reactions of proteins

• protein + H₂O → _enzymes amino acid

carbohydrates

general name for organic compounds occuring in foods & living tissues

monosaccharides

one sugar molecule

• glucose

disaccharides

two sugar molecules (monosaccharides)

polysaccharides

more than 10 sugar molecules (monosaccharides)

• polymers of monosaccharides monomers that form by condensation polymerisation

hydrolytic reaction of carbohydrates

polysaccharides + H₂O→ _enzyme dissacharides

dissacharides + H₂O→ _enzymes monosaccharides (glucose monomers)

hydrolytic reaction of fats & oils

triglyceride + 3H₂O → _enzyme glycerol + 3 fatty acids

synthesis/condensation of proteins

• amino acids → proteins + H₂O

synthesis/condensation of carbohydrates

glucose monomers → starch/glycogen

synthesis/condensation of fats & oils

glycerol + 3 fatty acids → fats & oils