AS unit 2- Edexcel EVERYTHING in 8 pages

apart from green chemisty as thats pretty straight forward. If i have something wrong then i wrote it out myself sooo my bad.

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Bonding and intermolecular Forces:
Electron Pair repulsion theory can help you predict shapes of molecules and ions
Linear 180°
Triganol Planar 120°
Tetrahedral 109.5°
Triganol Bipyramidal 90° and 120°
Octahedral 90°
Lone pairs of electrons count toward an area of electron density but as they repel to a
much greater extent they reduce the bond angle by 2.5°
Bond lengths are subject to bond strength the stronger the bond the smaller the bond length
such as dipoles and double/triple bonds
Electronegativity is the ability of an atom to attract the electrons in a covalent bond giving the
bond ionic properties.
Differences in electronegativity will cause permanent Diapole interactions
Polar bonds are subject to difference in electronegativity
Polar molecules are nonsymmetrical and have polar bonds
Significance of polar bonds:
In organic chemistry they usually break first and always break heterolytically giving
Determines reaction mechanism
Using bond character data you can determine whether a bond it likely to be ionic or covalent
Ionic bonds can be distorted by electronegativity giving covalent characteristics
Experiments to determine whether molecules in liquids are polar or nonpolar
Stream of polar liquid will be deflected away from a charged rod
Mixing Solutions in known polar solvents. Nonpolar and polar liquids are immiscible
London (van der Waals) forces
Exist between all atoms
Size of force is relative to size of electron cloud
Susceptible to distortion and electron density shifts (induced ­ instantaneous dipoles)
Permanent Diapole
Differences in electronegativity
Aldehydes, Keytones, Carboxylic acids, Esters and Amides
Hydrogen Bonding
H must be bonded to one highly electronegative atom with an unpaired electron
H bonds are the strongest intermolecular forces and give molecules unusually high
melting and boiling points
Carbon Allotropes
Diamond 4 sigma bonds in a tetrahedral arrangement gives very strong properties
(giant covalent structure)
Graphite 3 sigma bonds with the 4th electron delocalized which allows for electrical
conductivity and weak bonds between graphite layers
Fullerenes C32 or more very strong ball shape such as the Bucky ball with a
delocalized electron

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Nanotubes tube versions of fullerenes however if embedded in polymers will conduct
Physical Properties in relation to intermolecular forces
Carbon chain length increases = boiling temp increases as there are more London
forces which requires more energy to break
Branching increases = boiling temp decreases as less overlap between chains so
less London forces
Hydrogen bonds reduce volatility of molecules such as alcohols compared to alkanes,
they are much stronger than London dispersion forces
Hydrogen halides boiling temps increase down the group due to…read more

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Ionization energies decrease down group 2 because
Atomic radii increase so less influence from positive nucleus
Electron shielding increases
Reactions of group 2 elements with:
Oxygen solid metal oxides
Water hydroxides and H2 (only elements below Ca)
Chlorine solid metal chlorides
Reactions of group 2 oxides with:
Water hydroxides
Dilute acid corresponding chlorides and nitrates with H20
Group 2 hydroxides will also neutralize dilute acids production chlorides or nitrates with 2H20
Group 2 sulfates solubility…read more

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Flame colours arise when energy from the flame allows the outer electron to jump to a higher
energy level shell and when the electron returns it emits a wave length which is seen as
visible light
1. Mix ground salt with HCl (conc HCl as chlorides are chlorides are soluble and volatile)
2. Dip nichrome wire (inert metal)
3.…read more

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Trends in reducing agent strength is shown by the reaction of potassium halides with conc
sulphuric acid
Reaction Observation Test
H2SO4 + KCl KHSO4 + HCl HCl gas is seen as
white fumes
H2SO4 + KBr Initially same as Cl so HBr is SO2 turns acidified
produced, potassium
But HBr is oxidised by acid dichromate(VI) paper
into Br and H2SO4 is yellow to green
reduced to SO2
H2SO4 + KI HI is immediately oxidised to Hydrogen sulfide
I2 consequently H2SO4 is turns lead ethanoate
reduced…read more

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Catalysts reduce activation energy by providing a lower energy alternative reacting pathway
which can be shown with a reaction profile
Factors influencing reaction rates can be demonstrated practically:
Evolution of gas
Colour change
Change in mass
Titrimetric analysis
Conductimetric analysis (ions present)
Dynamic state which can only be established in closed systems
Reversible reactions also never go to completion
Equilibrium is subject to:
Changes in temperature, endothermic reactions favour hotter temps and exothermic
favour cold temps
Changes in pressure/concentration from high to low gradient…read more

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Bioethanol is produced by the fermentation of plants and can be used as a
combustion fuel, raises debates into carbon neutrality and food vs. fuel
Alcohol and Sodium produce hydrogen gas and a white precipitate with is an ionic salt
such as sodium propanoxide
o Alcohol also acts as a weak acid by donating a H+
Substitution with a halogen produces halogenoalkanes
Oxidation of primary alcohols requires an oxidising agent such as K2Cr2O7 in H2SO4.…read more

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Chloroalkane can prepared with HCl and shaking with alcohol, as Cl is highly reactive
no catalyst is required
Iodo/Bromoalkanes require an acid catalyst however has sulfuric acid is a very
strong oxidising agent some of the KBr used in the substitution reaction make be
oxidised which reduced the yield. As for KI the reaction will not complete so a weaker
acid is required
o KX acts as a halide carrier which is reacted with the sulfuric acid in to the HX
Purifying organic liquids
1.…read more

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Bond breaking can occur differently and is usually subject to the polarity of the bond
Homolytic bond fission : electrons are shared between the 2 species in the bond
producing free radicals
Cl2 2Cl
Heterolytic bond fission: electrons are kept by one atom producing electrophiles and
HCl H+ + :Cl
It is useful to classify reagents as you can predict what time of reaction mechanism will
Polar bonds always break heterolytically
Nonpolar bonds usually break homolyticaly
Nucleophiles attack +
Electrophiles attack electron rich…read more



Good document. Very helpful is there more info on group 2 and 7 stuff. Didn't get that part too well.

Thank you

Hashem Khan

What other notes for green chemistry


Isn't phenolphthalein colourless in acid?


Btw "keytone" should be spelt ketone. Also, test for alcohols with PCl5 instead of potassium dichromate (VI), cause the later doesn't react with tertiary alcohols. Besides the occasional error, very clear and concise notes! :)


I suggest that you study about Group 2 and 7 from the Unit 3 notes as they're very helpful and concise.

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