Download Reactions of Metals and Their Compounds

Unit 7 - Reactions of Metals and
Their Compounds
Chapter 8 in Text Books
Lesson Aims:
To understand the differences between
CHEMICAL and PHYSICAL reactions.
To know the different types of chemical
reactions
Chemical and Physical Changes
What is the important difference between and
CHEMICAL and PHYSICAL change?
PHYSICAL = the substance does not become a
new substance
CHEMICAL = a new substance is created
3 minutes – read p70 and discuss it.
CHEMICAL or PHYSICAL?
Draw a table in your books.
Choose whether the following are chemical or
physical changes, and why.
Types of Chemical Reaction
READING RACE…
What are the 4 main types of chemical reaction?
What happens in a combination reaction? (give
an example)
What happens in a single displacement
reaction? (give an example)
What happens in a decomposition reaction?
(give an example)
What happens in a double displacement
reaction? (give an example)
Answer race!
Using the questions on page 71…
GO!!!
CHEMICAL reactions
Reagents
1
2
3
Add 5mL of copper sulfate(CuSO4) to a small
piece of zinc(Zn) in a small beaker or petri dish
Collect 5mL of limewater(Ca(OH)2) in a test
tube. Gently blow through a straw into the test
tube until a change occurs.
Strongly heat 5g of copper carbonate(CuCO3) in
a test tube.
4
Add 5mL of barium chloride(BaCl2) to 5mL of
diluted sulfuric acid(H2SO4) in a test tube.
5
Add 5mL of lead nitrate (Pb(NO3)2) to 5mL of
potassium iodide(KI) in a test tube.
6
Add 5mL of sodium carbonate(Na2CO3) to 5mL
of dilute hydrochloric acid (HCl) in a test tube.
Observation Evidence for
Explanation
chemical reaction
Word equations : Equations in word
• Copper sulfate+ Zinc → Zinc sulfate + Copper
Zn + CuSO4 → ZnSO4 + Cu
• Calcium hydroxide + carbon dioxide → calcium carbonate + water
Ca(OH)2 + CO2 → CaCO3 + H2O
• Copper Carbonate (CuCO3) + Heat → Copper oxide(black powder CuO) +
carbon dioxide(CO2)
• Barium chloride (BaCl2) + Sulphuric acid (H2SO4) → Barium sulphate
(BaSO4) + Hydrochloric acid (HCl)
• Lead nitrate (Pb(NO3)2) + Potassium iodide(KI) → Lead iodide + Potassium
nitrate
• Sodium carbonate(Na2CO3) + Hydrochloric acid (HCl) → Sodium chloride +
water + carbon dioxide
If the empty space was taken out of all atoms...
the 7 billion people on Earth…
would be the volume of a sugar cube!
Atoms, Ions and Molecules
Lesson aims:
To understand how chemical reactions take place.
To know how covalent, ionic and metallic bonding
occur.
Vocabulary Review
Backs to the boards…
(But before we start, you have 3 minutes to review our
last Chemistry unit!)
METAL
PERIODIC TABLE
ATOM
ELECTRONS
VALENCE ELECTRONS
Nucleus
Reading Race!
…with a difference.
I will give you the answer, you have to write the question!
For example:
Answer = Ms. Lee
Question?
Who is the most awesome teacher in the world, with
beautiful long hair and a wonderful personality. And she
is very nice and funny too.
ANSWER:
atoms, ions or molecules
QUESTION:
What is all matter made of?
ANSWER:
Element.
QUESTION:
What is the name give for an atom that presents
the unique property of the kind? There are more
than 110 kinds being discovered so far.
ANSWER:
It depends on how many valence electrons there
are in its outer shell.
QUESTION:
What decides the type of bond an atom will
form?
ANSWER:
They try to get a full outer shell by losing,
gaining or sharing valence electrons.
QUESTION:
Why/How do atoms bond?
Not in your book…
ANSWER:
For most elements, 8.
QUESTION:
How many electrons are there in a complete
outer shell?
Obtaining a Complete Outer Shell
For the following elements, how many electrons
do they need for a full outer shell?
Oxygen
Atomic number = 8
Electron configuration = 2,6
O needs 2 more electrons
Chemical reactions = bonding = atoms obtaining a complete outer shell
Magnesium
Atomic number = 12
Electron configuration = 2,8,2
Mg needs to lose 2 electrons
Chemical reactions = bonding = atoms obtaining a complete outer shell
Sodium
Atomic number = 11
Electron configuration = 2,8,1
Na needs to lose 1 electron
Chemical reactions = bonding = atoms obtaining a complete outer shell
Hydrogen
Atomic number = 1
Electron configuration = 1
H needs to gain 1 electron more…
OR to lose 1 electron!
Chemical reactions = bonding = atoms obtaining a complete outer shell
Chlorine
Atomic number = 17
Electron configuration = 2,8,7
needs 1 more electron
Chemical reactions = bonding = atoms obtaining a complete outer shell
Argon
Atomic number = 18
Electron configuration = 2,8,8
It doesn’t need to do anything 
What is the name given for the group this gas
belongs to in the Periodic table?
Chemical reactions = bonding = atoms obtaining a complete outer shell
Do you remember what they are?
• CORE electrons:
Electrons that are in full shells. If we use the
example of Na (sodium) , the electrons in the first
shell ( 2 electrons) and the electrons in the second
shell ( 8 electrons) are both found in full shells.
These are the core electrons.
• VALENCE electrons:
The valence shell of the atom is the outermost shell
that contains electrons. Electrons in the outermost
shell are called valence electrons.
Three Types of Bonds
The 3 main types of bond are:
(find them!)
• COVALENT Bonds
• METALLIC bonds
• IONIC bonds
Chemical reactions = bonding = atoms obtaining a complete outer shell
Covalent Bonding
What is happening here:
Chemical reactions = bonding = atoms obtaining a complete outer shell
Covalent Bonding
Key facts:
- Between non-metal and non-metal
compounds.
- It is the sharing of electrons.
- Creates molecules.
Chemical reactions = bonding = atoms obtaining a complete outer shell
Covalent Bonded Molecules
Using the Molymods, create the following
molecules…
Chemical reactions = bonding = atoms obtaining a complete outer shell
An oxygen molecule
Chemical reactions = bonding = atoms obtaining a complete outer shell
A hydrogen molecule
Chemical reactions = bonding = atoms obtaining a complete outer shell
A carbon dioxide molecule
Chemical reactions = bonding = atoms obtaining a complete outer shell
A water molecule
Chemical reactions = bonding = atoms obtaining a complete outer shell
Molecules
MOLECULES are 2 or more atoms bonded together
in a covalent bond.
For example, water, oxygen, hydrogen, glucose even
DNA.
H2 O
C6H12O6
O2
H2
Chemical reactions = bonding = atoms obtaining a complete outer shell
Metallic Bonding
What’s happening?
VALENCE ELECTRONS
FREELY MOVING
SEA OF ELECTRONS
Metallic Bonding
The valence electrons of the metal
atoms move around freely between
atoms creating a “sea of electrons”.
Because the metal atoms loses
electrons to the sea, they are
positively charged (why?).
The positive metal IONS are
attracted to the negative electrons
= METALLIC BONDING.
Ionic Bonding
How would sodium and
chlorine complete an outer
shell?
Na: 2,8,1 (lose one)
Cl: 2,8,7 (gain one)
(2 minutes) Tell each other again…
QUESTION RACE
Page 75,
GO!!!
Atoms, Ions and Molecules
Lesson aims:
To understand how chemical reactions take place.
To know how covalent, ionic and metallic bonding
occur.
Chemical Salts
Lesson aims:
To know what happens when a metal and acid
react.
Which Salt?
Salts have many uses. For example, which salt is
used as a flavour enhancer?
Table salt = sodium chloride!
Which salt makes you poop a lot?
Which salt is used to make fluffy pancakes?
Which salt is used to help plants grow?
Which salt is used for drawing on blackboards?
Three Reactions To Learn
metal + acid
metal oxide + acid
metal carbonate + acid
Let’s see what happens!!
Metals + Acid
What happens when we react a metal with an acid?
Try it and observe…
Magnesium and dilute sulphuric acid
(write down your observations)
How do we know what gas it is?
SET FIRE TO IT!!!
Collect the gas like this as seen on p77.
When collected, put a burning splint into the gas
(don’t let it escape).
POP!!
= H2
Try to write a word formula:
magnesium + sulphuric acid  magnesium
sulphate + hydrogen
Mg + H2SO4  MgSO4 + H2
Other Acids
magnesium + various acid  salts + hydrogen
magnesium + sulphuric acid 
magnesium sulphate + hydrogen
magnesium + hydrochloric acid 
magnesium chloride + hydrogen
magnesium + nitric acid 
magnesium nitrate + hydrogen
Metal Oxides + Acids
copper oxide + sulphuric acid  ??
Write down your observations.
copper oxide + sulphuric acid
 copper sulphate + water
CuO + H2SO4  CuSO4 + H2O
Summary so far…
Metal + acid 
Metal oxide + acid 
Metal Carbonate + Acid
CaCO3 + H2SO4  CaSO4 + CO2 + H2O
calcium carbonate + sulphuric acid
 calcium sulphate + carbon dioxide + water
Summary
Metal + acid 
Metal salt + hydrogen
Metal oxide + acid 
Metal salt + water
Metal carbonate + acid 
Metal salt + carbon dioxide + water