organic chemistry igcse extended

alkane

• CnH2n+2

• undergo substitution reaction /w chlorine

alkenes

• CnH2n

• manufactured by cracking long chain alkanes using high temp & catalyst

• in addition reactions, react with aqueous bromine, hydrogen w nickel catalyst, acid catalyst

alcohol

• CnH2n+1OH

• made by ethene reacting with steam

• burnt in air/oxygen to produce carbon dioxide and water

• balanced: C2H5OH + 3O2 → 2CO2 + 3H2O

carboxylic acid

CnH2n+1COOH

functional group

atom or group of atoms that determine chemical properties of a homologous series (ex: alcohol → hydroxyl group)

homologous series

• same functional group

• same general formula

• differ by a CH2 unit per member

• trend in physical properties

• similar chemical properties

saturated compound

molecules where all carbon-carbon bonds are single bonds

unsaturated compound

molecules that have double carbon-carbon bonds

drawing isomer

• stack carbon on top of each other

• change position of double bonds

• make it look as weird as possible

meth

1 carbon

eth

2 carbon

prop

3 carbon

but

4 carbon

pent

5 carbon

hex

6 carbon

hept

7 carbon

oct

8 carbon

name ester

• alcohol → -yl

• carboxylic acid → -oate

• alcohol name in front, carboxylic acid in back

• ex: methtyl ethanoate from methanol and ethanoic acid

hydrocarbons

contain ONLY hydrogen and carbon

substitution reaction

one/ a group of atoms replaced by another/ a group of atoms

test for double bond (if its unsaturated)

• add aqueous bromine

• color change from orange to colorless

addition reaction

two reactants form one product

polymer

large molecules built up from many smaller molecules (monomers) joined by covalent bonds

environmental challenges caused by plastics

• disposal in landfill sites

• accumulation in oceans harming aquatic life

• greenhouse gases released when burning

• carbon monoxide gases released when incomplete combustion happens

addition polymers

• formed by many unsaturated monomers (have C=C double bond)

• C=C bond is removed from monomer to form saturated polymer

• long chains of C-C single bonds

condensation polymer

• formed from monomers with two functional groups

• small molecule such as water produced

• can be polyesters with ester linkages OR polyamides with amide linkages

cracking

breaking down larger hydrocarbons to produce smaller molecules

depolymerisation

• chemical process in which a polymer is broken down into smaller monomer units

• happens through heat, hydrolysis, oxidation, etc

addition vs substitution

• addition unsaturated ; substitution saturated

• addition single products ; substitution two products

addition vs condensation polymerization

• addition from unsaturated monomers (alkenes w C=C bonds) ; condensation from two different monomers with two functional groups

• condensation has byproducts

• addition form single bonds ; condensation form ester (COO) or amide (CONH)

how do you know if something is used to make a polymer

it has a 1:2 ratio of carbon to hydrogen (an alkene)

Trend of crude oil from bottom to top

• Chain length decrease

• Volatility higher

• Boiling point lower

• Viscosity lower