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CHEMISTRY 1

UNIT 1: FORMULAE AND EQUATIONS
IONS

In groups 1, 2 and 3, the ionic charge is the same as group number
...
g
...
Groups 6 and 7 are 2- and - respectively
...
g
...

-ate: The most common oxyanion, e
...
NO3- (Nitrate), SO4- (Sulphate), BrO3- (Bromate)
...
g
...

hypo- : An oxyanion with two oxygens less than the -ate ion, and one less than the -ite ion, e
...
NO(Hyponitrite), SO2- (Hyposulphite), BrO- (Hypobromite)
...
g
...

thio- : An oxyanion with one oxygen replaced with sulfur, e
...
NSO2- (Thionitrate), S2O3- (Thiosulphate),
BrSO2- (Thiobromate)
...
They’re usually metal hydroxides,
e
...
LiOH, Ca(OH)2
IONIC EQUATIONS

In an ionic equation, you only show the molecules that change their charge, and ignore any that stay the same
...
The SO4 doesn’t change its charge,
so it’s a spectator ion, and is left out
...
Charge is always conserved
...

The rules for solubility are as follows:
➢
➢
➢
➢
➢
➢

All Sodium, Potassium and Ammonium salts ARE soluble
...

All Sulphates ARE soluble EXCEPT FOR Barium, Lead and Silver
...

All Group 1 Carbonates ARE soluble, all other carbonates AREN’T soluble
...


Solubility in water is dependent on whether or not the substance has a dipole
...
Something like Potassium Fluoride (KF) will dissolve very readily, as it has a large dipole
...
It would however dissolve in a
solvent with no dipole, like an ester
...
If it has no dipole, it’ll dissolve in a solvent with no dipole
...
Reduction is the loss of Oxygen, or the gain of
electrons
...
You can use the acronym OIL RIG to help remember
the difference between oxidation and reduction:

Oxidation Is Loss, Reduction Is Gain
Consider the following ionic equation:
2+
2+
𝐶𝑢(𝑎𝑞)
+ 𝑀𝑔(𝑠) ⟶ 𝐶𝑢(𝑠) + 𝑀𝑔(𝑎𝑞)

The Copper has gained electrons, so was reduced (reduction is gain)
...

The oxidation number is the number of electrons an atom has lost
...
All of the oxidation states in an ion add up to the overall charge
...


2

Here are the oxidation rules:
➢
➢
➢

Group 1 and 2 metals have oxidation numbers of +1 and +2 respectively
...

Oxygen is always -2, except for peroxides, where it’s +1
...
g
...


UNIT 2: BASIC IDEAS ABOUT ATOMS
STRUCTURE OF ATOMS

Particle
Proton
Neutron
Electron

Charge
+1
0
-1

Mass
1
1
Negligible

Position
Nucleus
Nucleus
Orbitals

All atoms are neutral, and have an equal number of protons and electrons
...
An isotope is an atom with the same number of protons, but a
different number of neutrons
...

RADIATION

Certain isotopes are unstable, and stabilise by emitting radiation
...
The
half-life of a radioisotope is the amount it takes for half of the nuclei in a sample to decay
...
Ionising radiation injures living cells by
damaging the cell membrane, and heating up the insides of the cell
...

ALPHA

Alpha radiation is the ejection of a Helium nucleus ( 42He2+) from the atom
...
Alpha particles are positively charged, and so
are attracted to the negative pole of a magnetic field
...
The proton stays in the nucleus, and
the electron is expelled
...
The mass number stays the same, but atomic number
goes up by one
...
In a magnetic field, it’s attracted to the positive pole
...
This gives off a positron, an electron neutrino
and large amounts of energy
...
It’s as
penetrative as beta plus decay
...
Here’s an
example:
50
25𝑀𝑛

→

50
24𝐶𝑟

+ 01𝑒 + 00𝜐e

ELECTRON CAPTURE

Electron capture is when the electron with the lowest energy level collapses into the nucleus, and combines
with a positron to make a neutron
...
As the
electron closest in is drawn into the nucleus, all the other electrons with higher energy levels collapse down to
lower levels
...
Atomic number goes down
by one, and mass number doesn’t change
...
They are very
penetrative, and can travel through a meter of concrete
...

USES OF RADIOISOTOPES

Isotope
Iodine - 131
Cobalt - 60
Carbon - 14

Use
Chemotherapy
Radiotherapy
Carbon Dating

Isotope
Strontium - 90
Iodine - 131
Cobalt - 60

4

Use
Thickness Control
Medical Tracers
Coal Analysis

ELECTRONIC STRUCTURE

Shell
1
2

Makeup
1S2
2S22P6

3
4

3S23P63D10
4S24P64D104F14

The S shell has one orbital, which holds one pair of electrons
...


The P shell has 3 orbitals, which hold three pairs of electrons
...


The shell with the lowest energy level is always filled first
...

IONISATION ENERGY

If given enough energy, an electron will leave the atom
...

The ionisation energy is the energy it takes for one mol of electrons to leave one mol of substance
...
The general formula for this is:
+
𝑋(𝑔) ⟶ 𝑋(𝑔)
+ 𝑒−
+
2+
𝑋(𝑔)
⟶ 𝑋(𝑔)
+ 𝑒−

The factors that affect the ionisation energy are:
➢
➢
➢
➢

The more protons in the nucleus, the stronger the pull, so the higher the I
...

The further the electron is from the nucleus, the weaker the pull, so the I
...
is lower
...
This lowers I
...

If an electron is paired, its partner will repel it slightly, so I
...
is lower
...
The charge just before a big jump in I
...
is usually the
most common ion
...
This is because there’s less shielding
between this next shell and the nucleus
...
There are more protons in each nucleus, but that’s
counteracted by the extra shielding, and the distance the electron is from the nucleus
...
But
there are a few exceptions
...
This is because the electron in Boron has an extra full S
shell between it and the nucleus
...

Oxygen (Group 6) is lower than Nitrogen (Group 5)
...
This causes
extra repulsion, and counteracts the extra proton
...
If it’s shot with less energy than the ionisation energy, only certain frequencies are absorbed
...
So, when these exact frequencies of
light are absorbed, it’s the electron being promoted to a higher energy level
...
The highest energy level is usually about level 7
...
The first line is
the promotion to n=2, the second line is the promotion to n=3, etc
...
The lines eventually get infinitely close
...

6

According to the internet, the ionisation energy of Hydrogen is 2
...
You can verify this by looking at
the graph
...
3 PHz
...
3x1015 S-1 x
6
...
188x10-18 J
...

The Balmer series is the energy required to promote the electron from n=2
...

The absorption spectrum and the emission spectrum are the same
...
An electron
will always fall down to the lowest energy level possible, as it’s more stable
...


UNIT 3: CHEMICAL CALCULATIONS
MASS

Atomic Mass (Ar): The average mass of an atom relative to one twelfth of the mass of one Carbon - 12 atom
...
The Mr of a substance is the
mass of one mol of that substance in grams
...

There are five steps to the process:
1
...

3
...

5
...

Ionisation: The substance is shot with an electron gun
...

Acceleration: The substance is passed through charged plates, which accelerates it to very high speeds
...
Different atoms are deflected
different amounts, depending on their mass and charge
...


The inside of a mass spectrometer is a vacuum, so none of the ions collide with other particles, which could
alter their course
...

SIMPLE MASS SPECTRA

7

This is the mass spectrum of Chlorine
...
They have masses of 35 and
37
...
There are three, because there are three different combinations
of Cl ions: 35 and 35, 35 and 37, and 37 and 37
...
Using this you can work out the relative
abundances of the Cl2 ions
...
75 𝑥 0
...
375

74

𝐶𝑙2 =

37

𝐶𝑙 + 35𝐶𝑙 = 0
...
75 = 0
...
25 𝑥 0
...
0625

You can also work out the Ar of chlorine, by multiplying each isotope by its abundance:
35 𝑥 0
...
25 = 35
...
The empirical formula is the
simplest ratio of these atoms
...
If you’re given the Mr too, you can work out the molecular formula, e
...

A liquid Y has an Mr of 88
...
5% Carbon, 36
...
1% Hydrogen
...

0
...
96𝑔 [𝐶] 47
...
364 𝑥 88 = 32
...
03/16 ≈ 2𝑚𝑜𝑙[𝑂]
0
...
01𝑔[𝐻] 8
...
The empirical formula is the simplest ratio of these, so 𝐶2 𝑂𝐻4
...
I
...
A mole is 6x10 23 particles of something
...
It is defined as the number of atoms in 12 grams of Carbon - 12
...
You can find how many mols of a substance you have by dividing the
mass you have by its Mr
...
g
...
145𝑚𝑜𝑙[𝐾2 𝐶𝑂3 ]
138𝑔𝑚𝑜𝑙 −1
𝐾2 𝐶𝑂3 : 𝐾𝐶𝑙 = 1: 2
0
...
29𝑚𝑜𝑙[𝐾𝐶𝑙]
0
...
5𝑔𝑚𝑜𝑙 −1 = 21
...
If you have the masses of the real
and theoretical yield, you can work out percentage yield by dividing the actual yield by the theoretical one,
and multiplying by 100
...

CONCENTRATION

The concentration of a solution can be measured in moldm-3 or in gdm-3
...

To get concentration in grams, divide the mass by the volume
...
This changes under different conditions
...
4dm3
...

By first using a balanced equation to work out the mols of gas produced, you can find out the volume of gas
produced
...

To work out the molar volume for a given set of conditions, you can use the equation:
𝑉1 𝑃1
𝑉2 𝑃2
=
𝑇1
𝑇2
You could also use the ideal gas equation:
𝑉=

𝑛𝑅𝑇
𝑃

Where: P = Pressure (KPa), V = Volume (dm3), n = Amount (mols), R = Molar Gas Constant (JK-1Mol-1), T =
Temperature (K)
...
For example, the error on a biuret
whose divisions are 0
...
05
...

You can work out percentage error by dividing the absolute error by the total reading, and multiplying by 100
...

You must write out your answers to the correct amount of significant figures
...
1% is 4
...
The metal gives electrons to fill the outer shell of the nonmetal
...
It’s usually shown with a dot and cross diagram
...
Charge must be written on both ions
...

Ionic bonds are weaker than covalent bonds
...
This is when two atoms share an electron, to
give both a full outer shell
...
They’re
much stronger than ionic bonds, and are drawn like this:

Or like this:

A coordinate bond is a type of covalent bond, but instead of one electron coming from each atom, one of the
atoms gives both
...


POLAR BONDS

Most bonds aren’t purely covalent or purely ionic
...
If there’s a huge electronegativity difference, the bond is ionic
...
This means the electron pair is not quite in the middle, it’s pulled more towards the more
electronegative species
...
A dipole is a very slight
difference in charge, denoted by δ+ or δ-
...

If more electrons happen to be on one side of a molecule, that side will be δ-
...

The dipole governs many physical properties, such as melting and boiling points, solubility, and reactivity
...
A
strong dipole also means that Van der Waals’ forces are stronger, so the boiling point will be higher
...

HYDROGEN BONDING

A Hydrogen bond occurs when hydrogen bonds with a very electronegative element, most commonly Oxygen,
but it could also be Fluorine, Chlorine or Nitrogen
...
Compounds with hydrogen bonds have unusually high melting
points and boiling points, and are very soluble
...
It depends on the number of occupied
orbitals (pairs of electrons) around an atom
...
Lone pairs
repulse more than bonded pairs
...
5° / 28°

➢

6 Bonded Pairs - Octahedral - 90°

➢

2 Bonded Pairs, 2 Lone Pairs - Bent - 104°

11

➢

3 Bonded Pairs, 1 Lone Pair - Pyramidal - 107°

UNIT 5: SOLID STRUCTURES
COORDINATION NUMBERS

The coordination number of an ion is how many of the anions surround each ion when it’s bonded in a lattice
...
Caesium’s is 8
...
Their structures look like this:

CARBON ISOMERS

There are two main isomers of Carbon - diamond and graphite
...

Each C is bonded to four others covalently
...
Diamond is a very hard
material, and has a very high boiling point
...

Graphite is layered in hexagonal layers, where each carbon is bonded to three others
...
The layers are free to slide over each other,
making graphite very soft
...


IODINE AND ICE

Iodine is a purely covalent molecule, so Van der Waals’ forces are very weak between Iodine molecules
...

Ice has a giant tetrahedral structure, that’s held together by Hydrogen bonds
...

METALLIC BONDING

Metallic bonding involves a sea of loose electrons between the atoms
...
The more free electrons there are in the structure, the better a conductor it is
...
They aren’t soluble on their own, as
they have no dipole
...
In these, there is very little dipole,
so boiling point is very low, and they aren’t soluble
...

Giant molecular substances - These compounds contain many covalent bonds, so tend to have high boiling
points
...
They don’t conduct, with the notable exception of
graphite
...
They have high boiling points, and
don’t conduct when they’re solid
...
When dissolved,
they split into their constituent ions, and so conduct well
...
There are eight groups (plus the transition metals),
and seven periods
...

FLAME TESTS

Ion
Mg2+
Ca2+
Sr2+
K+

TRENDS IN GROUP

Colour
Colourless
Orange - Red
Red
Lilac

Ion
Ba2+
Li+
Na+

Colour
Pale Green
Red
Orange

2 REACTIONS

As you go down Group 2, the reactions get more vigorous
...
The reactions with water get more violent as you go down the
group
...

THERMAL STABILITY OF GROUP

2 CARBONATES AND HYDROXIDES

As you go down the group, the Group 2 carbonates get more stable
...
This means the CO2 can
escape more easily, and so the carbonate is less stable
...

HALIDES

Here are the tests for halide ions:
Ion
ClBrI-

Water Precipitate
White
Cream
Yellow

Ammonia Solubility
In strong ammonia
In weak ammonia
None

As you go down group 7, the elements become less reactive
...
As a result of this, it attracts electrons less, and so is less

13

attractive
...
If halides react with iron, you can get different results
...

As you go up the group, the halides become stronger oxidising agents
...
So, Chlorine is a stronger
oxidising agent
...
Some
people are against this though
...

SOLUBILITY OF GROUP

2 HYDROXIDES AND SULPHATES

Hydroxides become MORE soluble as you go down the group
...

Sulphates become LESS soluble as you go down the group
...

SOLUBLE AND INSOLUBLE SALT FORMATION

To form a soluble salt, for example Sodium Chloride, here are the steps:
➢

➢
➢
➢
➢

Choose two suitable reagents, which will form the desired salt, and leave a precipitate behind
...
These would form the desired Sodium Chloride, and a
Magnesium Carbonate precipitate
...

Then, filter out the precipitate
...

Leave it for a week, while the remaining water evaporates naturally, and you’ll be left with crystals of that
salt
...
An example for
this case would be Ba(NO2)2 and MgSO4
...

You must then add these two reagents to water, and shake or stir thoroughly
...

Wash the precipitate with water, and then bake it in the oven to dry it
...
Here’s the method:
➢
➢
➢
➢
➢
➢

Weigh about 0
...

Measure out 100cm3 of water using a measuring cylinder, and add it to the beaker
...

Slowly add 20cm3 of Silver Nitrate, and then another 5cm3
...

Heat the solution for about 10 minutes, without letting it boil
...

Weigh some filter paper, and then collect the precipitate in it
...
Then minus
the mass of the filter paper, and you’re left with the mass of the Silver Chloride
...


UNIT 7: EQUILIBRIA AND ACID BASE REACTIONS
EQUILIBRIA

Not all reactions go to completion
...

This symbol (⇌) is used to show a reversible reaction
...

3𝐻2 + 𝑁2 ⇌ 2𝑁𝐻3
A dynamic equilibrium is when the rates of forward reaction and backwards reaction are the same
...
A reaction in a closed system will always continue until it reaches dynamic
equilibrium
...
’
This principle is useful in industry, to maximise the yield of a certain product
...

➢
➢
➢

If you increase temperature, the equilibrium will shift in the endothermic direction
...

If you increase pressure, equilibrium will shift towards the side with the fewest mols of substance
...
This
number is called the equilibrium constant, or Kc
...
Temperature, however, does change Kc
...

ACIDS AND BASES

An acid is a proton (H+) donator
...
This is called
dissociation
...

A base is a proton (H+) acceptor
...
Ammonia is also a base
...
Most alkalis have the hydroxide ion
...
It’s a logarithmic scale, and uses base 10
...
That is, it either uses or releases energy
...

The enthalpy change of a reaction is often shown written after it
...
A positive number means the system has gained energy, so it’s
endothermic
...

Δ𝐻𝑐𝜃 [𝑋(𝑔) ] = The enthalpy change of complete combustion in oxygen
...

Δ𝐻𝐷𝜃 [𝑋(𝑔) ] = The enthalpy change of dissociation
...
All elements are in their natural states
...
For example:
𝐶𝐻4 + 2𝑂2 ⟶ 𝐶𝑂2 + 2𝐻2 𝑂
Compound

Δ𝑯𝜽𝒇 (KJMol-1)

CH4

-72

O2

0

CO2

-394

H2O

-286

First, work out the energy released by turning the reactants back into their constituent elements
...

−394 + 2(−286) = −966𝐾𝐽𝑀𝑜𝑙 −1
Then, just add the two together to get the total enthalpy change:
72 − 966 = −894𝐾𝐽𝑀𝑜𝑙 −1

1

ENTHALPY CHANGE IN SOLUTION

You can find the enthalpy change in solution by doing a calorimeter experiment, and then putting the results in
the following formula:
Δ𝐻 =

−𝑚𝑐Δ𝑇
𝑛

Where: m = mass of the liquid (1 cm3 = 1g), c = the specific heat capacity of water, ΔT = the temperature
change of the water, n = Number of mols of the reactant (the metal)
...

BOND ENERGY

You can also use Δ𝐻𝐷𝜃 to work outΔ𝐻
...
g
...
5(498) = 3582
𝐵𝑜𝑛𝑑𝑠 𝐹𝑜𝑟𝑚𝑒𝑑 = 4(413) + 346 + 745 + 2(464) = 3671
Δ𝐻 = 𝐵𝑜𝑛𝑑𝑠 𝐵𝑟𝑜𝑘𝑒𝑛 − 𝐵𝑜𝑛𝑑𝑠 𝐹𝑜𝑟𝑚𝑒𝑑 = 3582 − 3671 = −89 𝐾𝐽𝑀𝑜𝑙 −1

UNIT 2: RATES OF REACTION
RATES

Studying rates of reaction is useful in industry, and in studying body processes
...

The following factors affect the rate of reaction:
➢
➢
➢
➢
➢

Concentration
Temperature
Catalysts
Pressure
Light

2

➢

Surface Area

You can measure the rate of reaction in several ways
...
g
...

➢ The rate a reactant is used up, e
...
measuring the mass of a carbonate using a balance as it thermally
decomposes
...
You can do this using a data logger, and a filter of the opposite colour of the precipitate
...

GRAPHS

Volume of oxygen over time, from the thermal decomposition of hydrogen peroxide (rate a product is
formed)
...


The effect on the concentration of the reactants on rates of reaction
...
In a successful
collision, bonds break and new ones are formed
...
This means more successful collisions
...
This means they move quicker, so collide more often, but also when they
collide they have more energy, so the collision is more likely to be successful
...


This is a Maxwell - Boltzmann graph
...
As you can see, at T2, the higher temperature, more of the molecules have energy higher
than the activation energy
...

CATALYSTS

A catalyst lowers the activation energy of a reaction, which leads to more successful collisions
...
A catalyst increases rate of reaction by providing an alternate route for the
reaction to take, which requires less energy
...


4

IODINE CLOCK

An Iodine clock reaction can be used to measure the rate of a reaction, if I2 is one of the products of a reaction
...
It also reacts with sodium thiosulphate, which
causes no colour change
...

So, if you add a certain amount of sodium thiosulphate, say one mol, to the reaction above, and then some
starch, the solution will turn blue when one mol of Iodine has been produced, because all of the sodium
thiosulphate has been used up, and the iodine will react with the starch
...
These include CO2, CO and SO2
...
It contributes to climate change,
which harms the environment
...
It is a very toxic gas, and can be
fatal to humans
...

SO2 comes from impurities in hydrocarbons, mainly coal
...

THE ECONOMY

In industry, it’s important to keep costs as low as possible, to maximise profits
...

LIMESTONE QUARRYING

Limestone is a very valuable natural resources, but some problems arise during its quarrying
...
It also involves a lot of noise pollution, and all the industry
releases greenhouse gasses, which harm the environment
...
As you add more and more carbons, the surface area of the molecule gets larger
...
If
something has a certain isomer which has a smaller surface area, that isomer will have a lower boiling point
...
g
...
This shows exact structure, e
...


𝐻

−

𝐻
|
𝐶
|
𝐻

−

𝐻
|
𝐶
|
𝐻

−

𝑂
∥
𝐶
|
𝑂𝐻

𝐻

−

𝐻
|
𝐶
|
𝐻

𝐻
|
− 𝐶 −
|
𝐻−𝐶−𝐻
|
𝐻

𝐻
|
𝐶
|
𝐻

−

𝐻

Shortened Formula - like the molecular formula, but shows the functional group and structure as well, e
...

𝐶2 𝐻5 𝐶𝑂𝑂𝐻, 𝐶𝐻3 𝐶𝐻2 𝐶𝐻2 𝐶𝐻3
Skeletal formula - shows the spine of the molecule, leaving out any unimportant molecules, e
...


STRUCTURAL ISOMERISM

An isomer is a molecule made of the exact same elements, but which is arranged differently and has different
properties
...
g
...

Functional Group Isomerism - this is when the functional group changes, e
...
Ethanoic Acid and Methyl Methanoate
...
g
...

ELECTROPHILES, NUCLEOPHILES AND FREE RADICALS

An electrophile is a species that’s attracted to a negative charge (electro - electron, phile - attracted to)
...
A nucleophile has an unbonded pair, which goes on to form a covalent bond with a negatively
charged molecule
...
Because of this, radicals are very reactive, and react very quickly
...
They have no charge
...
This leads to one positive ion and one
negative ion
...
g
...
g
...
It also produces toxic Carbon
Monoxide, and Carbon soot
...
All single covalent bonds are σ
bonds
...
They can happen between any two combinations of
shells, S and S, P and D, etc
...
The electrons aren’t held
between the two nuclei, but hover in clouds above and below the molecule
...
A double covalent bond contains one σ bond and one π bond
...
This means they’re much more
reactive then alkanes, which don’t have a π bond
...
This is a photochemical reaction,
which means it’s initiated by light, specifically UV light
...
If both species are on the same side of the bond (both above or both below) this is the Z isomer (Z for
zammen (same))
...
e
...


Priority is always given to the species with the highest mass, so, for example, if around a bond you had
Chlorine, Hydrogen, Bromine and Bromine, the geometric isomers depend on where the two Bromines are,
not the Chlorine
...
This
makes it much easier to visualise the isomerism, like in the picture below:

ELECTROPHILIC ADDITION

Curly arrows are used to show the movement of a pair of electrons
...
In step one, the positive
bromine takes the two electrons from the π bond, and forms a covalent σ bond with the carbon on the left
...
The C
on the right becomes positive
...

In step 2, the negative bromine is a nucleophile, as it’s attracted to the positive charge, and has an unbonded
pair of electrons
...


8

UNSYMMETRICAL ELECTROPHILIC ADDITION

The process above is symmetrical, so only has one product
...
In general, in this situation, the hydrogen bonds to the carbon which
already has the most hydrogens attached to it
...
When this happens, you get
the major (most stable) product
...


In the picture, you can see that the H bonds onto the CH 2 not the CH, because it has more Hs
...
The minor product would be 1 - bromo propane, where the H and Br swap places
...

The speed of this reaction depends on the strength of the Hydrogen - Halogen bond
...
The same reaction, but with hydrogen fluoride instead of
hydrogen bromide would take longer
...
This is because the bromine, which makes it brown,
becomes part of the alkene, in an electrophilic addition reaction
...
The alkene gets
oxidised into a diol
...
The required conditions
are:
➢
➢

150℃
Nickel catalyst

This may seem like a pointless reaction, as ethene is a very valuable compound, used for fuel and plastics, but
ethane is used in the production of margarine
...
Polymerisation is a good
example of this, where thousands of alkenes join to make one polymer
...
The conditions for this reaction are:
➢
➢

200℃
2,000 atm (202MPa)

Plastics have many uses
...
Polythene is used for carrier
bags
...


9

Polymerisation always happens around the double bond, and it’s easier to draw the monomer the same way
you would for an E - Z isomer, with everything around the bond written in shorthand to avoid confusion
...
The bromine is eliminated
from the molecule
...
The equation is this:

The hydroxide ion takes one of the hydrogens from the compound, forming water
...

This reaction can be used to test which halogens are present in a halogenoalkane
...
Chlorine will give a white precipitate, bromine will give a cream one, and
iodine will give a yellow one
...
As a result the Carbon is 𝛿 + , and the
halogen is 𝛿 −
...
It then comes in and
joins with the Carbon, donating its lone pair to form a covalent bond with the Carbon
...
The OH ion must approach from the
side away from the halogen, as it’s repelled by the electrons in the halogen
...
Fluorine - Carbon is a very
strong bond, and so is very hard to break
...
The bond strength overpowers
any difference in polarity
...
They were used very widely, in fridges, aerosols and anaesthetics
...
This is because CFCs cause a huge amount of damage to the ozone
layer, which protects the earth from harmful UV radiation
...
This chlorine radical reacts
with the O3 to form O2
...

The weaker the Carbon - Halogen bond, the higher it’s potential to destroy the ozone layer
...

REFLUX

Heating under reflux involves heating organic compound to make reactions go faster
...
To prevent any gasses
from escaping, reflux involves attaching an air tight condenser to a flask or beaker, so any gasses condense and
fall back into the flask
...
The required conditions are:
➢
➢
➢

300℃
65 atm
Phosphoric acid catalyst

This is a very inefficient reaction
...

PREPARATION OF ETHANOL BY FERME NTATION

This process is done by adding yeast (or other bacteria) to certain crops, such as maize
...
The mixture is then distilled, to separate the pure alcohol from the mixture
...
Alcohols burn well in air, to produce water and CO 2
...

Here are some advantages and disadvantages to using biofuel instead of fossil fuels:
Advantages

Disadvantages

It has the potential to be Carbon neutral

It makes less energy gram for gram than fossil fuels

It’s renewable

It’s more expensive

It can be produced from waste

It uses large amounts of land, which could be used
for growing food

It can be produced locally

The process is never really Carbon neutral, as heavy
machinery is almost always used
...

The catalyst for this reaction in the BACKWARD direction (to produce ethanol) is an excess of water
...
Backwards, it’s an addition reaction
...
This simply refers to the number of R groups the
carbon attached to the OH group is attached to
...


As alcohols get longer, the polar OH group has less and less of an effect on the molecule
...
As the chains get longer, alcohols act more
like regular hydrocarbons
...
This is because the relative stability
of all of the C - H bonds cancels out the polar OH bond
...
The Chromium is reduced from Cr (VI) to Cr (III), and turns from orange to green
...
If you did the reaction under reflux,
more oxidation would occur, and you’d get the carboxylic acid
...
A secondary alcohol produces a ketone, not an aldehyde or a carboxylic acid
...

Tertiary alcohols cannot be oxidised, as there are no hydrogens around the OH bond for it to take
...
If the orange solution
turns green, then the alcohol is primary or secondary
...


13

REACTIONS OF CARBOXY LIC ACIDS

The test for a carboxylic acid is to add Sodium Hydrogen Carbonate
...
The reaction is:
𝐶𝐻3 𝐶𝑂𝑂𝐻 + 𝑁𝑎𝐻𝐶𝑂3 ⟶ 𝑁𝑎𝐶𝐻3 𝐶𝑂𝑂 + 𝐻2 𝑂 + 𝐶𝑂2
The salt formed is called a Metal -anoate
...
In this
equation it’s Sodium Ethanoate
...


An ester is named -yl -anoate
...


This compound is called Ethyl Propanoate
...
If you heat them to a
temperature between their boiling points, one of them will boil, and the other wont
...


UNIT 8: INSTRUMENTAL ANALYSIS
INFA RED SPECTRA

Spectroscopy is used to identify molecules
...
The two main types of movement are streching and bending bonds
...
The wave number is the reciprocle of
wavelength, and is the number of waves per unit distance
...


14

NUCLEAR MAGNETIC RESONANCE

The nucleus of an atom , similar to an electron, has spin
...
A Hydrogen - 1 nucleus,
or a proton, has spin
...
If it’s shot with the right amount of energy, usually radio waves, it’ll flip
directions
...
The electrons
in the bond absorb some of the energy, and so it requires more energy to reverse the polarity of a proton if it’s
bonded strongly
...
This will tell you what the carbon is
bonded to
...


15



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