Transcript Additional Chemistry

The stuff you need to know.
Particle
Mass
Charge
Proton
1
+1
Neutron
1
0
Electron
0
-1

ATOMIC MASS
12.0
6
C
ATOMIC NUMBER


As long as you know
the differences
between the particles
in an atom the PT can
tell you how many
each contains.
Atomic Mass =
Protons + neutrons.
Atomic number =
Protons (electrons)
Atom
Sodium
Chromium
Nitrogen
Oxygen.
Protons
Neutrons
Electrons
1
GROUPS
2
3
4
5
6
7
PERIODS
1
2
Non metals
3
4
Metals
MAKING BONDING EASIER:
GROUP NUMBER =
Knowing the periodic table will help you
first work out what bonding is taking place
(ionic, covalent or metallic).
The number of electron on
the outer shell
It will also help you to get the atomic
structure of each atom right.
PERIOD NUMBER =
The number of shells
8
Type of Bonding
Between what
atoms
Characteristics
Properties
IONIC
Non Metals Metals
Electrons are
exchanged, metal
atoms give them to
the non metal atoms
producing ions
Large crystals with
high melting points
that will conduct
electricity when
molten or dissolved.
COVALENT
Non Metals – Non The non metals
share pairs of
Metals
Either small
molecules like CO2
or giant crystals like
diamond.
Metals - Metals
Shiny, good
conductors of heat
and electricity.
electrons
METALLIC
Metals lose their
spare electron to a
sea of delocalised
electrons around the
positive metal ions
Draw the structures of each atom
and then show the bonding that
would occur.
1. Magnesium and Chlorine to form
Magnesium Chloride.
2. Nitrogen and Hydrogen to form
Ammonia.


As each atom has a mass so
does a molecule made from
different atoms. This is
MOLECULAR MASS (The
mass of a molecule).
We can work out molecular
mass by simply adding
together the masses of the
atoms that make a molecule

1.
2.
3.
What are the masses
of the following?
H2SO4
CaCO3
Mg(OH)2
The reason we call the masses of atoms and
molecules relative masses is because they are relative
to each other (we don’t need to compare them to
anything else) We make use of this when using
MOLES
Atom economy is a measure of the amount of useful stuff
we get from a reaction.
CaCO3(s) → CaO(s) + CO2(g)
To find the atom economy we divide
The useful stuff from
the relative mass of useful stuff by the
this reaction is CaO
relative mass of everything used and
times by 100
Mr of useful products
Atom economy =
× 100
Mr of all reactants
56
100  56%
100



We use MOLES to work out how much stuff
will be either needed, or made during a
chemical reaction.
A MOLE OF ANY ATOM OR MOLECULE IS
EQUAL TO ITS ATOMIC MASS OR
MOLECULAR MASS IN GRAMS.
1 MOLE OF ANY SUBSTANCE WILL
ALWAYS CONTAIN THE SAME NUMBER
OF PARTICLES (6.023 × 1023)
Mass
Moles 
Ar / Mr
Work out the number of moles in the
following:
1. 80g of Copper sulphate (CuSO4)
2. 5.75g of Sodium metal (Na)
Fe2O3(s) + CO(g) → Fe(s) + CO2(g)
Make a list of the
number of atoms
on each side.
Fe × 2
O×4
C×1
Fe × 1
O×2
C×1
Try to find the
easiest one to
balance first
Fe2O3(s) + CO(g) → 2Fe(s) + CO2(g)
Keep working at it
changing the
numbers as you go
and eventually you
will crack it
Fe × 2
O×4
C×1
Fe × 2
O×2
C×1
Sometimes you
can’t balance one
thing without
changing another
Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g)
(s) = solid
(l) = liquid
(g) = gas
(aq) = Solution
‘For a reaction to occur particles must collide with
sufficient energy to overcome the activation energy of the
reaction.’
Condition
Effect
Raising the
Temperature
Particles move around faster so they collide
more often and with more energy.
Increasing the
concentration /
Pressure
There are more particles in an area so they
collide more often.
Increasing the
surface area
There are more surfaces available for the
particles to collide with.
Adding a catalyst.
Lowers the activation so more particles have
enough energy to start a reaction.
Positive electrode
(Anode)
Negative electrode
(Cathode)
Negative ions are
attracted to the anode
where they give up their
electrons and become
oxidised
Positive ions will be
attracted to the
cathode where they
will gain electrons and
become reduced
Eg:
Eg:
2Cl-(aq) → Cl2(g)+ 2e-
Cu2+(aq) + 2e- → Cu(s)
You need to know how electrolysis is used in:
•The production of Aluminium
•The purification of Copper
•Production of Hydrogen, Chlorine and Sodium Hydroxide from Brine
N2(g) + 3H2(g) ↔ 2NH3(g)
In Reversible reactions
products are able to turn back
into reactants
-92kJmol-1
They will eventually reach a state
of dynamic equilibrium where the
products are turning back into
reactants as fast as they are
produced
If you change the conditions of an equilibrium it will try to change them
back!
1. Increase the temperature and it will try to lower it by using the
endothermic reaction and visa versa.
2. Increase the pressure and it will make less molecules in order to
decrease the pressure again and visa versa.
3. If you add more of anything in the equilibrium it will move the other
way to get rid of it and visa versa.
•Acids are substances that donate Hydrogen ions (H+)
•Acids can be both strong and weak.
H2SO4 → 2H+ + SO42•Bases are solids or liquids that neutralise acids
•They are able to accept Hydrogen ions (H+)
•They can be Metal Hydroxide or Metal Oxides
HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)
CuO(s) + 2HCl(aq) → CuCl2(aq) + H2O(l)
Salts are produced in neutralisation reactions, most are