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TransitionMetals
Key Objectives:
You should be able to:
• List the general physical
properties of metals
• Describe the general chemical
properties of metals
e
...
reaction with dilute acids and
reaction with oxygen
• Explain in terms of their
properties why alloys are used
instead of pure metals
• Identify representations of alloys
from diagrams of structure
• Deduce an order of reactivity
from a given set of experimental
results
• Describe the reactivity series as
related to the tendency of a metal
to form its positive ion, illustrated
by its reaction, if any, with:
– the aqueous ions
– the oxides
of the other listed metals
• Describe and explain the action of
heat on the hydroxides, carbonates
and nitrates of the listed metals
• Account for the apparent
unreactivity of aluminium in terms of
the oxide layer which adheres to the
metal
• Name the uses of copper related
to its properties (electrical wiring
and in cooking utensils)
• Name the uses of mild steel (car
bodies and machinery) and
stainless steel (chemical plant and
cutlery)
• Explain the uses of zinc for
galvanising and for making brass
• Describe the idea of changing the
properties of iron by the controlled
use of additives to form steel alloys

Periodic Table:
Transition elements
Transition elements are all metals that are found in the elongated
section of the Periodic Table between Groups II and III
...


Physical Properties:
- are harder and stronger
than the elements in
Group I
- have higher densities
than the elements in
Group I
- have higher melting
points than the elements in Group I
Chemical Properties:
- form coloured compounds, e
...
copper(II) sulphate crystals are blue, and
potassium(VII) manganate purple
- the elements and their compounds show catalytic activity, e
...
iron in the Haber
process and vanadium(V) oxide in the Contact process
- have variable oxidation states, e
...

iron can form Fe2+ and Fe3+ ions
...
This is
because the ions in a metallic
element are all the same size
...
Therefore, an alloy retains its shape much better

particularly strong, an alloy is often used

than a pure metal when a force is applied
...

In alloys, such as brass, bronze and steel, the metallic
element is mixed with small amounts of another element
or elements
...
This
prevents the rows of metallic ions from sliding over each

Conversion of Iron into steel
Pig iron contains about 4% carbon and other non-metallic impurities,
such as phosphorus, silicon and sulphur
...
The transition elements that are used and the
proportions in which they are added determine the properties of the
steels that are formed
...

• This causes oxidation of some of the carbon to carbon dioxide,
and sulphur to sulphur dioxide, both of which escape as gases
...

• Calcium oxide (quicklime) is added
...

The amount of carbon remaining can be controlled depending on
the type of steel required
...
5%
carbon and 99
...

Transition elements are then added in exact quantities to produce
different types of steel
...


Reactivity series
Metals can be placed in

alkaline hydroxide and

produce a salt and

order of their reactivity

hydrogen gas, for

hydrogen, for example:

with other elements,

example:

Fe(s) +2HCl(aq) -> FeCl2(aq) + H2(g)

which is known as the

Ca(s) + 2H2O(l) -> Ca(OH)2(aq) + H2

reactivity series
...


for reference to

water
...


more rapidly when heated
with steam, for example:

Potassium, sodium and
calcium react with cold

Mg(s) + H2O(g) -> MgO(s) + H2(g)

water to produce an

Metals above hydrogen

aqueous solution of an

react with dilute acid to

Oxides of metals below
carbon are reduced to the
metal when heated with
carbon, for example:
2CuO(s) + C(s) -> 2Cu(s) + CO2(g)

Transition Metals
Displacement reactions
...
This means that it has a greater tendency to
form positive ions than copper
...


Deducing order
of reactivity of
metals
To put metals in order of

For instance, Cell 1 tells us

reactivity, reactions can be

that metal A (-) is higher in

attempted as in, for example,

the reactivity series than

adding a metal to an aqueous metal C (+) and 1
...


solution containing ions of

measurement of the

another metal or heating a

difference in reactivity
...
For example, if zinc powder is heated with
copper(ii) oxide, the following reaction occurs:
CuO(s) + Zn(s) -> Cu(s) + ZnO(s

metal with the oxide of

However, if zinc oxide is heated with copper, no reaction occurs
...
46V is a measurement of

containing two dissimilar

the difference in reactivity
...

The ease with which metallic hydroxides, nitrates and
carbonates decomposed when heated is related to the position
of the metallic element in the reactivity series
...
We say that they are stable to heat
...


Hydroxides

another metal
...
3)
...
Group I nitrates (except
lithium nitrate) decompose partially to form the metallic nitrite
and oxygen gas, for example: 2NaNO3(s) -> 2NaNO2(s) + O2(g)

reactivity between the two

Group I carbonates (except lithium carbonate) do not
decompose when heated
...
The
amount of heat required for decomposition if greater for
carbonates of very reactive metals, such as calcium carbonate,
CaCO3(s) -> CaO(s) + CO2(g)
but carbonates of less reactive metals like copper(II) carbonate
decompose at much lower temperatures:
CuCO3(s) -> CuO(s) + CO2(g)

Therefore, the order of the 3
metals in the reactivity series
is
Most reactive: A -> C -> B
:Least reactive

electrons and form positive
ions
...
Those of less reactive metals decompose into their
oxides and give off steam, for example:
Cu(OH)2(s) -> CuO(s) + H20(g)

Other metallic nitrates of less reactive metals decompose more
completely, producing the metal oxide and giving off nitrogen
dioxide (a brown gas) and oxygen gas, for example: !

Cell 2 tells us that metal C (-)

voltmeter (or EMF electromotive force)

metals
...
10V + 0
...
56V
...

Common error
Students often state that metals higher up in the reactivity series
decompose with much more difficulty than those lower down
...


magnesium and aluminium
a) cannot be extracted by chemical reduction
because the ores are not reduced by chemical
reducing agents, such as carbon, carbon
monoxide or hydrogen
b) cannot be extracted by electrolysis of aqueous
solutions, because hydrogen is formed at the
cathode instead of the metal
...

There are 3 general methods of extracting metals from
their ores:
1) Metals of average
reactivity, eg iron
and zinc, are
extracted by
chemical reduction
using carbon/carbon
monoxide as
reducing agents
...




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