Organic chem

Isomerism

Same molecular formula, different arrangment of atoms

Structural isomers

same molecular, different structural (chain/branch, func group positional, diff func group)

Steroisomerism

Same molecular, atoms occupy different positions in space

Geometrical isomers

cis/trans. Occurs due to restricted rotation around c=c bond.

Optical isomers

Occurs when molecules have chiral carbon (c atom bonded to 4 diff atoms/groups). Tetrahedrally and asymetrically arranged. Froms two non-superimposable mirror images, enatomers, which have same physical properties. Distingush by ability to rotate plane of polarised light in equal amounts of opposite direction.

Reflux

Uses heat to increase reaction rate and prevent loss of reactants and products. Maximises yield.

yield

minimise byproducts, maximise resource efficiency

Distillation

used to seperate two organic liquids on the basis of 2 different bpt. Lower bpt boils and evaporates first, moving down condenser where colled and returned back to liquid state

Boiling chips

used for smooth boiling, no spitting

Seperating funnel

Used in purifying product. seperated based on solubility/polarity. More dense liquid will be lower level.

Distillation can be used for

aldyhde collection which is formed before COOH forms in oxidation

Drying agent

Drying agent Na2SO4 absorbs remaining H2O, seperating.

Intermolecular forces

Forces of attraction between molecules

Van der Waals

• weakest

• between all atoms and molesules

• only type of IM force in non-polar molecules

• strength increases as atomic size increases

• temporary force occuring when electrons form temporary dipoles

Permanant dipole-dipole

• occurs in polar molecules/moleucles which have permanant dipoles

• middle strength

Hydrogen bonding

• H atom bonded to FON

• strongest

Condensation polymerisation

monomers join together causing loss of small molecule

Polyester

Polymer with ester linkages. Made with two -COOH groups and an OH with two -OH groups. Can be hydrolysed by H2O in both conidtions.

Polyamide

Polymer with amide links. Made with two amino groups and two HCL or two COOH groups. Can be hydrolysed.

Protein

Polymers with amino acid monomer with amid group and COOH group. Can be hydrolysed under acidic conditions.

Smells

Ester - fruity

Amine - fishy

COOH - vinegar

Litmus

Amine - basic

COOH - acidic

OH, aldehydes, ketones - react if insolube

Acyl chlorides - acidic

Esters, alkanes, alkenes - react if soluble

mpt and bpt increased when

length of chain increased

Felhings/benedicts

Warm, cloudy green to reddish if aldehyde not ketone. Forms Cu2O.

Tollens reagent

warm ammoniacal silver nitrate, silver mirror forms if aldehyde not ketone

Bromine water Br2(aq)

test if unsaturated eg c=c. orange to colourless if unsaturated, rapidly recolourises from orange. saturated, alkanes slowly decolourise over uv and/or heat.

Lucus - ZnCl2/conc. HCl

3^o OH - quick cloudiness

2^o OH - cloudy in 10mins

1^o OH - no cloudiness

way to identify acyl chlorides

H2O, produces white fumes of HCl - litmus used after turns acidic as COOH formed

hold HCl near compounds

Amine - dense white fumes

H2SO4

turns OH to ester, smelling sweet

Heated H^+/Cr2O7²- (K+ or Na+)

1^o OH - turns to COOH, orange to dark green

2^o OH - ketone, orange to dark green

3^o OH - no reaction

NaCO3

COOH - fizzes as CO2 releases.

MnO4²-

Alkene - decolourised, acidified

Alkene - purple to brown, MnO2 non acidic

Volatile substances

Small

• hydrocarbons

• haloalkanes

• OH

• COOH

• esters

Insoluble

• C>=4

• Haloalkanes

• Most esters

Mpt/Bpt

typically increased w/ length

MnO4^-/H+ in reactions

• Alkene to diol

• OH to =O

Alkene reactions (hint 4 reactions)

• haloalkane - Br2,Cl2,HBr,HCl

• Diol - KMnO4/H+

• OH - H2SO4 or H2O/H+

• Alkane - H2/PtNi

1o OH reactions (hint 4)

• Alkene - Heated conc H2SO4

• Aldehyde/COOH - Cr2O7²-/H+ or MnO4^-/H+

• Haloalkane - PCl,SOCl 5/2

• Ester - heated COOH/H+

Haloalkane reactions (hint 3)

• Amine - warm NH3(alc)

• OH - NaOH(aq)

• alkene - KOH/NaOH (alc)