Organic Flashcards
Functional group
atom or a group of molecules in an organic molecule that largely determines the molecules properties and reaction
for example -COOH, -OH, -NH2
Homologous series
A series of compounds with similar properties and the same general formula, in which each member contains one CH2 unit more than the previous member.
Hydrocarbon
A compound that contains carbon and hydrogen only
for example: alkanes, alkenes and alkynes.
Structural isomer
A compound with the same molecular formula, but different structures
Alkanes
- saturated hydrocarbon (only single bonds between carbons)
- general formula CnH2n+2
- Tetrahedral geometry
- Burns in oxygen to produce CO2 and H2O
- Does not decolourise bromine water
Alkenes
- An unsaturated hydrocarbon (one or more double bond present between carbons)
- general formula CnH2n
- Planar geometry
- Burns in oxygen to produce CO2 and H2O
- Decolourise Bromine water (orange to colourless)
Alkynes
- An unsaturated hydrocarbon (one or more triple bond present between carbons)
- general formula CnH2n ‐ 2
- Linear geometry
- Burns in oxygen to produce CO2 and H2O
- Does not decolour bromine water
functional groups naming priority
1) carboxylic acid
2) ester
3) amide
4) aldehyde
5) ketone
6) alchohol
7) amine
8) alkene
9) alkyne
10) alkane
11) haloalkanes
Solubility in Water
- Small alcohols, amines, aldehydes, carboxylic acids and amides are able to form hydrogen bonds with water and therefore are soluble in water.
- Water dissolves organic molecules by forming dipole‐dipole attractions and hydrogen bonds with them.
Complete Combustion
- hydrocarbon + oxygen —–> carbon dioxide + water
Incomplete Combustion
- hydrocarbon + oxygen —–> carbon monoxide + water
- hydrocarbon + oxygen —–> carbon + water
Substitution Reaction
(UV light)
- Alkane + halogen ————–> haloalkane + halogen halide
Substitution Reaction - Haloalkanes
The haloalkane react with the hydroxide ions (OH‐) to produce alcohols.
Addition of Alkenes – hydrogen halides
- Hydrogen halides (HF, HCl, HBr, HI)
- ALKENE + HYDROGEN HALIDE —-> HALOALKANE
Addition of Alkenes – Hydrogenation
(Ni catalyst + 150°C)
ALKENE + HYDROGEN. —————————–> ALKANE
Addition of Alkenes – Steam
(H3PO4 catalyst + 300°C + 60-70 atm)
ALKENE + WATER ———————————> ALOHOL
Production of Ethanol
(yeast catalyst)
C6H12O6 ———————-> 2CO2 + 2C2H5OH
uses : Solvent in perfumes, inks and glues, Fuel, To make esters (used in food flavourings) Alcoholic drinks
Oxidation of Primary Alcohols
Primary alcohols are oxidised by a strong oxidising agent such as acidified permanganate (H+/MnO4-) or dichromate solution (H+/Cr2O7-2)
PARTIAL- ALDEHYDES
FULL- CARBOXILIC ACID
Oxidation of Secondary Alcohols
- oxidising agents: acidified permanganate (H+/MnO4-) or dichromate solution (H+/Cr2O7-2)
- produce ketones
Formation of Esters
- Formed by reaction between Alkanol and Acid
- condensation reaction (produces water).
- More commonly referred to as an esterification reaction
- Conditions require concentrated H2SO4
Polymers
A “molecular chain” made up from many thousands of repeating units
Thermoplastic
• Chains loosely tangled together • No cross links
• Low melting point
• Can be remoulded
eg - plastic bags / cling wrap
Thermosetting
• Cross links between chains • Much higher melting points • Cannot be remoulded • Rigid and inflexible eg- kitchen bench coverings
Elastomers
• Can be stretched or deformed
• Regain their shape
• Only a few cross links
eg- rubber
LDPE
Low Density PolyEthene (LDPE) –> type of thermoplatic
• Formed under high temp and pressure
• Made of branched chains, that don’t fit together well ‐ AMORPHOUS
• Low melting point
• Soft and flexible
• Used to make carrier bags and Glad Wrap
HDPE
High Density PolyEthene (HDPE)
• Formed using a catalyst at much lower temperatures.
• Chains are not branched
• They fit together much better
• More crystalline and less amorphous.
• Forms a harder substance, used to make wheelie bins, classroom chairs, milk bottles etc
