Chem10
ORGANIC CHEMISTRY

organic molecules-from plants & animals / carbon chemistry; studies compounds of C except carbonates & CO2

Names of compounds (nomenclature)
organic molecules: based on # of C atoms in main chain
1=meth-, 2=eth-, 3=prop-, 4=but-
type of compound identified by suffix of name
-ane: alkane family- single bond bet C atoms
-ene: alkene family- 1 double bond bet C atoms
-ol: alcohol family- and O-H group on chain(C-O-H)
-oic acid: carboxylic (organic) acid family- C-O-O-H group (C: = O & -O-H)
(H atoms joined to C atoms)(# before name indicates place of bond)
chloro- = -Cl group; Cl atoml
bromo- = -Br group; Br atom

Fuels
Natural gas: found in petroleum, remains of plankton and other marine animals, mainly methane, little ethane
Petroleum-mixture of hydrocarbons, from remains of plankton, separated into diff fractions by fractional distillation
Fraction# of C atomsBP range (°C)Uses
Petroleum gas1 - 4< room tempgas for gas cookers
Petrol5 - 1035 - 75petrol: cars
Naptha8 - 1270 - 170petrochemicals
Kerosene/ paraffin10 - 14170 - 250fuel: aircraft, kerosene-lamps
Diesel15 - 25250 - 340fuel: buses, lorries
Lubricating oil19 - 35340 - 500lubricant, waxes & polishes
bitumen> 70> 500black substance to surface road
mixed w/ chemical > tar


Cracking: process where large molecules in heavier fractions broken down into smaller and lighter molecules by means of catalysts
Uses: make- 1more fuel (larger fractions seldom used, litter fractions often used, more useful, petrol, kerosene), 2alkenes (always make), 3H2

Homologous Series
-groups of organic compounds of same type, formula of 1 differs from previous by an extra -CH2 group of atoms, same chemical reactions, diff bp & mp (C atoms ^ > mp & bp ^)
Alkanes (CnHn+2)- generally used as fuels, sources: crude oil/petroleum, hydrogenation of alkenes
Alkenes (CnH2n)- double bond > more reactive than alkanes, used to make polymers, eg polyethene (for plastic bags), source: cracking
Alcohols (CnH2n+1OH)- covalent-made of non-metals, neutral- dont ionise, ethanol: most widely used alcohol (used as solvent, perfumes & chemical production, fuel, constituent of wine + beer, to make esters), made by
-fermentation
C6H12O6 > bact (yeast) > 2C2H5OH + 2CO2
(too low temp: very slow, too hot: yeast killed, opt 37°C, anaerobic resp, done w/o air, air contains bact & O2 cause alcohol > ethanoic acid, stop ethanol production)
-catalytic addition of steam to ethene (alkene + water): double bond broken > H & OH added to each C atom: ethene > ethanol
CH2CH2 + H2O > (conc H3PO4) > CH3CH2OH
Carboxylic acids (CnH2n-1OOH)- covalent, acids- ionise in water, made by oxidation of alcohols (methenol > methanoic acid,...) most important: ethanoic acid, used as food preservative, solvent to make insecticides, drugs, photographic goods, dyes, polymers

Organic reactions
-Substitution: alkanes H atom substituted by another atom, (light) energy needed to break covalent bond
ALKANE + Cl2 > LIGHT > CHLOROALKANE + HCl
ALKANE + Br2 > LIGHT > BROMOALKANE + HBr
 -Addition (need double bond): molecule added to alkenes > 1 product, molecule added: H (hydrogenation), H2O (hydration), Cl, Br (Cl, Br- reactive, no need catalyst) (catalyst: Ni/Pd/Pt-H2 / H3PO4-H2O)
alkenes- unsaturated, alkanes- saturated (max amt of H atoms, no more can be added)
Test for unsaturation (alkenes): red Br sol + unsaturated hydrocarbon reacts quickly > colourless (addition reaction) (+ saturated > reacts slowly)
1ALKENE + H2 > Ni/PD/PT > ALKANE
2ALKENE + Br2 > DIBROMOALKANE
3ALKENE + Cl2 > DICHLOROALKANE
4ALKENE + H2O > H3PO4 > ALCOHOL
 -Combustion: most organic molecules burn in O2 > H2O + CO2 (complete combustion), incomplete combustion: > H2O + C/CO (C-soot)
ALKENE/ALKANE/ALCOHOL + O2 > CO2 + H2O: complete
ALKENE/ALKANE + O2 > C + H2O: incomplete
 -Oxidation of alcohols: alcohols oxidised by oxidising agents- acidified potassium dichromate (VI), oxygen & acidified potassium manganate (VII)
ALCOHOL + (Cr2O7-2/O2/MnO4-) > CARBOXYLIC ACID
 -Esterification: alcohols + carboxylic > H2SO4 > ester + H2O, ethanoic acid + ethanol > conc H2SO4-catalyst > ethyl ethanoate, esters- 'sweet smell'
used as food additives, sweets, bubble gum
Ethyl ethanoate used as nail polish remover
Name of ester: prefix of (alcohol -ly > carboxylic acid -anoate)
ALCOHOL + CARBOXYLIC ACID > H2SO4 > H2O + ESTER

Isomerism
Isomers: molecules w/ same formula, but different structures, isomers: different chemical & physical properties (1/2-cholorpropane)

MACROMOLECULES
-v.big molecules, containing 1000's of atoms: many small molecules (monomer) join to form a polymer, diff macromolecules have diff molecules and /or linkages

Synthetic polymers
-man-made: synthesized by polymerisation, non- biodegradable (can't be broken down by bact) > pollution (plastics burnt > poisonous gases)

Addition Polymerisation:
unsaturated monomer w/ a double bond > double bond broken > join
Polyethene

PVC: polyvinylchloride


Condensation Polymerisation:
-OH from 1 monomer reacts w/ -H of other monomer > polymer + water (2 monomers join together & a small molecule is removed- usually water)
Nylon (polyamide)

Terylene (polyester)


Natural polymers
proteins, carbohydrates and fats: main constituents in food
Carbohydrates:
-(glucose, sucrose, glycogen, cellulose, starch) contain C, H, O in ratio 1:2:1
Hydrolysis: large carbohydrates > sugars, by boiling w/ dilute HCl


Proteins
-complex polymers built up from amino acids (monomers) (same linkage as nylon, but diff units) hydrolyzed w/ dilute HCl > amino acids


hydrolysis products (sugars- carbohydrates, amino acids- proteins) can be identified by chromatography

Fats: Fats & oil- esters of long-chained carboxylic acids & alcohols w/ 3 hydroxyl groups called glycerol (same linkage as Terylene, but diff units)
Fat + NaOH > Glycerol + Soap (NaOOC-)
saponification: hydrolysis of fats by boiling w/ NaOH to make soap


Natural polymer Monomer Uses
Starch Glucose Provide energy (energy store in plants)
Protein Amino acid For growth, enzymes
Fats Long-chained carboxylic acid + glycerol Provide energy
Cellulose Glucose Energy store

Synthetic polymer Monomer Uses
Terylene (polyester)Diol + dicarboxylic acid To make fibres for clothing
PVC- polyvinylchloride Chloroethene Water pipes, waterproof plastic sheeting, insulation for cables & wires
Polyethene Ethene Make plastic (film- wrapping, bottles, pipes,...)
Nylon Diamine + dicarboxylic acid strong fibres ()

Non-metals
The Particulature Natrue of Matter
Experimental Techniques
Atoms, Elements and Compounds
Stoichiometry + Mole Concept
Acids + Bases
Chemical Reactions + Electrolysis
Rate and Heat of Reactions + Reversible Reactions
The Periodic Table
Metals

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