14/15 Fall semester
Engineering Chemistry
Instructor: Rama Oktavian
Email: rama.oktavian86@gmail.com
Office Hr.: M.13-15, Tu. 13-15, W. 13-15, Th. 13-15, F. 09-11
Outlines
1. Metals and non-metals properties
2. Metals reactivity
3. Reaction with metals
4. Gas mixture
Metals properties
The Periodic Table is divided into….
Metals
Metals properties
The Periodic Table is divided into….
and non-metals
Metals properties
Metals properties
• They have high melting and boiling points (except mercury)
• They conduct electricity and heat.
• They have a high density.
• They are shiny (lustrous).
• They are malleable (can be moulded)
• They are ductile (can be stretched)
Non-Metals properties
Non-Metals properties
•
Have low melting and boiling points.
•
Are brittle.
•
Do not conduct heat or electricity well.
(except carbon)
Metals properties
Different metals are suitable for
different jobs.
Gold, silver and platinum are very unreactive but very
malleable - making them suitable for jewellery
Metals properties
Copper is malleable, ductile and it conducts heat
and electricity well.
It is also unreactive making it suitable
for holding and carrying water.
Metals properties
Aluminium is a reactive
metal, but it forms a
coating of very stable
aluminium oxide.
This, together with its lightness and malleability
gives it many uses from window frames to
insulation foil.
Metals properties
Iron ore is common and
iron itself is very strong.
It can be moulded into many
shapes
Metals properties
As it forms, iron oxide constantly flakes
away exposing more of the iron
underneath.
Remember:
Unfortunately iron is quite brittle (for a
metal) and also oxidises (rusts) easily.
Only iron oxide is called
rust.
No other metal rusts!
Metals properties
Like aluminium, zinc oxidises
to form a stable coating of
zinc oxide which protects the
iron underneath it.
This is called galvanising.
To prevent this happening,
iron is often covered with a
thin layer of zinc.
Metals properties
Sodium, Calcium and Magnesium
These three metals are all far too reactive to be
much use in their pure form.
They all make important compounds though.
Metals properties
Sodium
Sodium metal is so reactive it has to be kept in oil to keep it away from the
oxygen in the air..
Without the oil, sodium quickly oxides into useless sodium oxide
All the same, sodium is essential for both plants and animals.
The commonest source of sodium is common table salt –
Chloride.
Sodium
Metals properties
Calcium
Calcium is less reactive than sodium, but it still oxidises too rapidly for the
pure metal to have any uses.
Calcium compounds, however, are very important.
Calcium carbonate makes up about 10% of the earth’s surface – limestone, marble
and chalk.
Calcium compounds are essential for life – such as for making bones and milk.
Metals properties
Magnesium
Magnesium is less reactive then sodium or calcium.
It is still too reactive to have any uses in its pure form though.
Magnesium is easily obtainable from salts in sea water
Amongst other things, magnesium is essential for making chlorophyll.
Metals reactivity
…. so Group 1
metals are the
most reactive
Reactivity
Metals get more reactive as you
move left in the periodic table
Metals reactivity
…They also get
more reactive
as you go down
the table
Reactivity
Metals reactivity
Group 1 metals are
the most reactive.
then Group 2
and potassium
is more
reactive
than
sodium
Metals reactivity
Metals all form
(They do this by LOSING electrons)
Metals reactivity
Most non- metals form
(They do this by GAINING electrons)
Metals reactivity
Groups 1 – 13 form positive ions
Na+
Mg2+
Al3+
Metals reactivity
Group 14 elements don’t form ions
This is because they have 4 electrons in
their outer shell. It isn’t easier to gain 4
more or lose 4 - so they don’t do either!
Metals reactivity
Groups 15, 16 and 17 all gain electrons to form negative ions
N3-
S2-
Cl-
Metals reactivity
Group 18 elements don’t form ions either.
This is because they already have the full 8
electrons in their outer shell.
Metals reactivity
3
Li
11
Na
Group 1 metals all
have one electron in
their outer shell.
19
K
Rb
Cs
Fr
They can lose this
electron to form a
1+ positive ion
Metals reactivity
For instance:
3
Li
11
Na
lithium
lithium ion +
electron
19
K
Li
Li+
+
Rb
Cs
Fr
+
e-
Metals reactivity
2+
4
Be
12
Mg
20
Ca
Group 2 metals
have 2 electrons
in their outer
shell….
Be
2+
Mg
2+
Ca
2+
Sr
Ba
Sr
….. so they
form 2+ ions
2+
Ba
2+
Ra
Ra
Metals reactivity
Some metals, like iron, can form 2+
or 3+ ions
Fe
Fe
Fe2+
+
Fe3+
+
2e
3e
-
-
Non-Metals properties
Non-metals can form two types
of ion:
Monatomic ions
Polyatomic ions
(the ion is made from just
one non-metal element)
(the ion is made from more than one
non-metal element)
Cl
I
Br
O
2
S
2
-
-
-
= chloride
OH
= iodide
SO42
= bromide
NO3
= oxide
CO32
= sulphide
= hydroxide
-
= sulphate
-
= nitrate
-
= carbonate
-
HCO32 = hydrogen carbonate
Non-Metals properties
Non-metals can form two types
of ion:
Monatomic ions
Polyatomic ions
(the ion is made from just
one non-metal element)
(the ion is made from more than one
non-metal element)
Cl
I
Br
O
2
S
2
-
-
-
= chloride
OH
= iodide
SO42
= bromide
NO3
= oxide
CO32
= sulphide
= hydroxide
-
= sulphate
-
= nitrate
-
= carbonate
-
HCO32 = hydrogen carbonate
Reaction with metals
1. Metals react with oxygen to from oxides.
2. Metals react with water to form hydroxides and
hydrogen gas.
3. Metals react with acids to form salts and hydrogen
gas.
Reaction with metals
Metals react with oxygen (O2) to form
1.
oxides.
sodium
4Na
+
oxygen

sodium oxide
2Na2O
+
O2

calcium
+
oxygen

calcium oxide
2Ca
+
O2

2CaO
iron
+
oxygen

iron oxide
+
3O2

2Fe2O3
4Fe
Reaction with metals
2. Metals react with water to produce
hydroxides and hydrogen gas.
 sodium hydroxide + hydrogen gas
sodium
+
water
2Na
+
2H2O 
calcium
+
water
 calcium hydroxide + hydrogen gas
Ca
+
2H2O

2NaOH
Ca(OH)2
+
+
*Soluble hydroxides are called alkalis*
H2
H2
Reaction with metals
3. Metals react with acids to form
salts and hydrogen gas
potassium + hydrochloric acid  potassium chloride + hydrogen
2K
+
2HCl

2KCl
+
H2
potassium + sulphuric acid  potassium sulphate + hydrogen
2K
+
H2SO4

K2SO4
+
H2