Transcript Intermediate 1 Chemistry - Deans Community High School

Intermediate 1 Chemistry
S3 Revision
Atoms and Elements
Elements
If a solid, liquid or gas is made up of only one type of
atom we say it is an element. For example, consider a
tripod made up of iron:
These atoms are
ALL iron – there’s
nothing else in here
The structure of the atom
The Ancient Greeks used to believe that
everything was made up of very small particles. I
did some experiments in 1808 that proved this
and called these particles ATOMS:
Dalton
NEUTRON –
neutral, same
mass as
proton (“1”)
PROTON –
positive, same
mass as
neutron (“1”)
ELECTRON –
negative, mass
nearly nothing
Atoms and charges #1
Protons have a __________ charge
Electrons have a ___________ charge
Neutrons don’t have a charge
So if an atom contains charged particles
then why is the total charge on an atom
always zero???????????
Atoms and Atomic number
The atomic number of an element
always tells us the number of
_________ in the nucleus of each
atom.
We can find the atomic number on
most _________ _________.
As we go across a row from left to
right the atomic number goes up by
______.
Atoms and Atomic number #2
The atomic number for lithium is _____
The atomic number for carbon is _____
The atomic number for iodine is _____
The atomic number for copper is _____
The atomic number for tin is _____
A boron atom has ____ protons in its nucleus.
A calcium atom has ____ protons in its nucleus.
A gallium atom has ____ protons in its nucleus.
A uranium atom has ____ protons in its nucleus.
An oxygen atom has ____ protons in its nucleus.
Periodic table
The periodic table arranges all the elements
in groups according to their properties.
Vertical
columns are
called GROUPS
Mendeleev
Horizontal rows are called PERIODS
The Periodic Table
Fact 3: Most of the elements are metals:
These elements
are metals
H
e
H
Li
B
e
B
C
N
O
F
N
e
N
a
M
g
Al
Si
P
S
Cl
Ar
K
C
a
Fe
Ni
C
u
Zn
A
g
A
This line divides
Pt
metals from non-u
metals
Br Kr
I
H
g
Xe
These elements are
non-metals
The Periodic Table
Fact 4: (Most important) All of the elements in
the same group have similar PROPERTIES.
H
e
H
Li
B
e
B
C
N
O
F
N
e
N
a
M
g
Al
Si
P
S
Cl
Ar
K
C
a
Fe
Ni
C
u
Zn
Br Kr
E.g. consider the group 1 metals. They all:
A
g
1) Are soft
2) Can be easily
Pt
cut
3) React with water
A H
with
u ga
I
knife
Xe
Group 1 – The alkali metals
Li
Na
K
Rb
Cs
Fr
Group 0 (or 8) – The Noble gases
He
Ne
Ar
Kr
Xe
Rn
Group 0 – The Noble gases
Some facts…
1) All of the noble gases have
a full outer shell, so they are
very _____________
2) They all have low melting and boiling points
3) Helium is lighter then air and is used in balloons
and airships (as well as for talking in a silly voice)
4) Argon is used in light bulbs
(because it is so unreactive)
and argon , krypton and neon
are used in fancy lights
Group 7 – The halogens
F
Cl
Br
I
At
Compounds
Compounds
Compounds are
different to
elements. They
contain different
types of atoms joined
together. Here are
some examples:
Glucose
Methane
Sodium
chloride (salt)
Some simple compounds…
Methane, CH4
Water, H2O
Carbon
dioxide, CO2
Key
Hydrogen
Ethyne, C2H2
Oxygen
Sulphuric
acid, H2SO4
Carbon
Sulphur
Covalent Compounds
• Covalent bonds only appear in non-metal
compounds like water (H2O) and Carbon
dioxide(CO2)
• The compounds are also known as
molecules and the covalent bonds are
very strong between the non-metal atoms.
• Between all the molecules there is weak
forces holding them together.
Covalent Compounds
• Covalent Water Molecules (H2O)
weak bond
O
atom
H
H
O
H
atom
Strong
covalent
bond
H
atom
O
H
H
Ions in Compounds
• Ions are charged particles which are
contained in ionic compounds.
• Ions can be either positively charged (+) or
negatively charged (-)
• Ions are attracted to each other and form
very strong bonds.
Ions in compounds
• Ionic Compound
ions
Strong
bonds
Naming compounds
Fill in the blanks below using the table on the
previous slide to help you.
Copper and chlorine will make ________ _________
Iron and sulphur will make ________ _________
Magnesium and oxygen will make ________ _________
Calcium and fluorine will make ________ _________
_________ and ________ will make barium nitride
Naming compounds
Fill in the blanks below using the previous slide to
help you.
Copper, carbon and oxygen will make ________ _________
Lithium, sulphur and oxygen will make ________ _________
Calcium, nitrogen and oxygen will make _______ _________
Potassium, carbon and oxygen will make _______ ________
_______, _______ and _______ will make silver nitrate
Before
Mixtures
After
Element, mixture or compound?
Salty water
Hydrogen
Hydrochloric acid
Air
Diamond
Sodium chloride (salt)
Elements, compounds or
mixture
Decide whether each of the samples is an element,
mixture or compound.
Salt water = _____________
Hydrogen = _____________
Hydrochloric acid = _____________
Air = _____________
Diamond = _____________
Salt = _____________
Solutions
and
separating
Dissolving things – some meanings
If a substance CAN be dissolved it is __________
If a substance CANNOT be dissolved it is _________
Words – soluble, solute, solvent, solution, insoluble
Distillation - separating liquids
Distillation can be used to
separate water and ethanol
because they have different
_______ ______. The
______ will boil first, then
turn back into a _______ in
the condenser and collect in
the _______. The water will
stay in the round flask, as
long as the _______ does
not go above ______OC.
Distillation is used to
separate crude _______ into
useful fuels like petrol.
Words – 100, temperature, oil, boiling points, ethanol, beaker, liquid
Separating mixtures summary
1) A mixture containing a solid and a liquid can be
separated using __________
2) A mixture of liquids with different boiling points can be
separated using _________
3) A mixture of different inks can be separated using
_______
4) Water can be removed from a solution by
___________
5) Separation methods are _____ chemical reactions
because a _____ substance is not being made.
Distillation, not, chromatography, new, evaporation or
filtration
Saturated
solutions
Consider our previous work on solutions:
Clearly, there is only so much
solute a solution can take…
A mixture that cannot take
any more solute is called a
“saturated solution”
Solubility words
Draw lines to match up the words to their meanings. One
has already been done for you.
Something that CAN dissolve is described as being…
Solute
How much of something that can be dissolved is
called…
Solution
Something that CANNOT be dissolved is described
as being…
Solvent
A solution that CAN’T dissolve anything else is…
Soluble
The solid that will be dissolved is the…
The mixture of solute and solvent is called the…
The liquid that the solute will be dissolved into is
the…
Insoluble
Saturated
Solubility
Chemical Reactions
Testing for oxygen
Oxygen will make a glowing splint _______
Testing for hydrogen
Hydrogen makes
a ___________
splint go
_______.
“POP”
Testing for carbon dioxide
Carbon
dioxide
Gas
Limewater
Carbon dixoide
makes
___________
go __________
Adding acids to metals
Some metals react with acids to produce ________ gas. The gas will make
the mixture _______ and the metal will eventually be _______ _____.
Some metals, like _______ and _______, are so unreactive that nothing
will happen.
Words – gold, hydrogen, bubble, copper, used up
Adding acid to carbonates
Carbonates are compounds that react with acids to make _________
__________ gas. This makes the mixture _________. When all of the
carbonate is used up the _________ will stop.
Limewater
goes cloudy
Carbonates used to be used as building materials but aren’t any more
because acid rain would eventually ________ the building.
Words – dissolve, bubble, carbon dioxide, bubbles
Acids and Alkalis
Name_____________________
Universal Indicator and the pH scale
Universal Indicator changes colour depending on whether it is
in an acid, alkali or neutral solution.
1
2
3
Stomach acid
4
5
6
Lemon juice
7
8
9
10
11
12 13 14
Water Soap Baking powder Oven cleaner
Below 7 is
_____
Above 7 is
_________
Exactly 7 is
_________
Quiz on acids and alkalis
Acid, alkali or both???
1) This has pH of less than 7 ____________
2) This is often used in cleaners or soap __________
3) This would turn Universal Indicator red ________
4) Sodium hydroxide is an ____________
5) This would feel soapy on your skin _________
6) This could burn your skin _________
7) This will turn universal indicator purple _________
8) Lemon juice and vinegar are examples of weak _______
9) limewater (calcium hydroxide) is an example of this__________
Neutralisation
An acid and alkali will cancel each other out (neutralise) each
other if the correct amounts are used
Acid + alkali
Salt + water
E.g. hydrochloric acid + sodium hydroxide
sodium chloride + water
This reaction is called ________________ because the
acid is used up and _________ is made.
Choose your answers from the list below:
combustion
respiration
neutralisation
hydrogen
water
oxygen
Complete the blank spaces
Adding sodium hydroxide to hydrochloric acid will make
water and a salt called sodium _________.
Adding sodium hydroxide to nitric acid will make water and
a salt called sodium _________.
Adding potassium hydroxide to sulphuric acid will make
water and a salt called _________ _________.
Adding magnesium hydroxide to hydrochloric acid will make
water and a salt called _________ _________.
Adding lithium hydroxide to sulphuric acid will make water
and a salt called _________ _________.
Adding
acid
to
carbonates
Carbonates are compounds containing carbon and oxygen.
When an acid and a carbonate are added together, the
mixture starts to fizz. A gas called _________ _________
is produced.
The limewater
will go
__________
Complete the blanks spaces
Adding sodium carbonate to hydrochloric acid will make carbon dioxide,
water and a salt called _________ _________.
Adding sodium carbonate to nitric acid will make carbon dioxide, water
and a salt called __________ _________.
Adding potassium carbonate to sulphuric acid will make carbon dioxide,
water and a salt called ___________ _________.
Adding magnesium carbonate to hydrochloric acid will make carbon
dioxide, water and a salt called ___________ _________.
Adding copper carbonate to sulphuric acid will make carbon dioxide,
water and a salt called _________ _________.
Reactions
of
metals
with
acids
When a metal reacts with an acid a gas called ______________ is
made. A salt is also made at the same time.
METAL + ACID
SALT + ____________
The name of the salt depends on the metal and the acid.
e.g. magnesium + hydrochloric acid
magnesium chloride + hydrogen
Complete the following reactions:
Calcium + hydrochloric acid
_________ ________ + __________
Zinc + hydrochloric acid
_________ ________ + __________
Iron + nitric acid
_________ ________ + __________
Lithium + sulphuric acid
_________ ________ + __________
These reactions are not neutralisation because _________
is not being made.
Useful acid-alkali reactions
1) Hydrochloric acid is used in the stomach
to help digest food. If we eat too many
“rich” foods our stomachs make too much
______. This is called _____________.
Indigestion tablets take away this pain
because they ______________ the acid.
2) Soil is often acidic, mainly due to acid ____. This can
have bad effects on ______ and vegetable growth.
________ is an alkali that farmers and gardners add to
soil to _________ the acid.
Words – plant, indigestion, neutralise,
rain, acid, neutralise, lime
Uses of acid reactions
When acids react new chemicals called salts are made.
These salts have many uses.
Sodium chloride is the chemical name
for table salt that we put on our chips.
Salts that are made from nitric acid contain
nitrate. Nitrates are needed by plants to
help them grow. Chemical companies use
nitric acid to make nitrate salts for farmers
to use as fertilisers for their crops.
Nitrate salts are also used in explosives.
Acid gases
The names of three acid gases are:
_________ _________
_________ _________
_________ _________
When fossil fuels like coal, _____ or natural _____
are burned in power stations, the carbon contained
in them reacts with oxygen to form ___________
dioxide gas. Carbon dioxide also comes out of car
exhausts.
A car engine needs a spark to set the petrol on fire. The energy from the
spark makes nitrogen and oxygen join together to make the acid gas
called__________ dioxide gas.
Some fossil fuels contain sulphur. When the
fuel burns, the acid gas called
_________dioxide is made.
Problems with acid gases
The acid gases called _________
dioxide, _________ dioxide and
_______ dioxide dissolve in cloud
droplets and fall as _____
______.
The acid rain gets into
rivers and streams and
kills ______. It can kill
______ when it falls
onto their leaves.
Acid rain can also damage stone
buildings and metal structures
because it reacts and eats them away.
The reactivity series
of metals
Metals
with
oxygen
When a metal is heated with oxygen it will glow and turn
into a METAL OXIDE. . The colour and brightness of the
glow can tell us about how reactive the metal is.
Metal
Magnesium
Observation
Very bright
white glow
Copper
Dull red glow
Iron
Bright red
glow
The order of reactivity most to least is ____________
then ____________ then ____________.
Order of reactivity
To work out which metals were more reactive than
others the number of bubbles made in one minute were
counted.
Magnesium made 28 bubbles in one minute
Tin made 10 bubbles in one minute
Zinc made 17 bubbles in one minute
Copper made 0 bubbles in one minute
Calcium made 34 bubbles in one minute
Aluminium made 23 bubbles in one minute
Iron made 13 bubbles in one minute
Reactivity series so far
A reactivity series of a list of metals in order of how
_________ they are. The ________ reactive metal
goes at the top of the list.
Most
____________
Put these lithium
reactive
metals in
magnesium
order of
reactivity: copper
iron
____________
____________
____________
calcium
____________
tin
____________
sodium
____________
aluminium
____________
potassium
____________
zinc
Least
____________ reactive
Reactions of Metals
You need to know 3 reactions of metals:
METAL + OXYGEN
eg magnesium + oxygen
METAL + WATER
eg calcium + water
METAL OXIDE
magnesium oxide
METAL HYDROXIDE + HYDROGEN
calcium hydroxide + hydrogen
METAL + ACID
e.g. magnesium + hydrochloric acid
SALT + HYDROGEN
magnesium chloride + hydrogen
Complete the following reactions:
1) Lithium + water
_______ _______ + _________
2) Lithium + hydrochloric acid
_______ _______ + _________
3) Silver + oxygen
_______ _______
4) tin + hydrochloric acid
_______ _______ + _________
5) Potassium + oxygen
_______ _______
6) Aluminium + oxygen
_______ _______
7) Magnesium + water
_______ _______ + _________
8) zinc + hydrochloric acid
_______ _______ + _________
9) Lithium + oxygen
_______ _______
10) calcium + hydrochloric acid
_______ _______ + _________