Metals Flashcards
Where are metals found in the periodic table?
metals are found on the left of the table- to the left of the ladder which starts above aluminium and steps down to the right
List five properties of metals
conducts electricity and heat
shiny
malleable
ductile
some are magnetic
Which group is called the alkaline metals?
Group 1
Li
Na
K
Rb
What group is called the Alkaline Earth Metals?
Group 2
Be
Mg
Ca
Sr
What is special about the transistion metals?
They form colourful compounds
&
They often have more than one valency
Fe 2+ and Fe 3+
What group are called the Halogens?
Group 7
F
Cl
Br
I
They are all diatomic!
What group is called the noble gases?
Group 0
He
Ne
Ar
Kr
they all have a full outer shell and are inert (unreactive)
Name the four metals less reactive than hydrogen in the reactivity series
Hydrogen
Copper
Silver
Platinum
Gold- unreactive
Name the five metals more reactive than carbon in the reactivity series
potassium
sodiium
calcium
magnesium
aluminium
carbon
All these metals must be extracted using electrolysis as carbon cannot displace them as it is less reactive
Name the four metals between carbon and hydrogen in the reactivty series
Carbon
Zinc
Iron
Tin
:Lead
Hydrogen
These metals can be extracted from their ores using carbon or coke in a blast furnace
Why can iron be reduced or extracted from its metal ore using coke (carbon)?
Carbon is more reactive than iron
Carbon displaces iron
iron is reduced
Henry threw some copper into some hydrochloric acid. He expected to see a reaction, some fizzing, but nothing happened. explain why?
copper is less reactive than hydrogen
copper cannot displace hydrogen and so it does not react
Describe three properties of the group 1 metal sodium
soft - can be cut with a knife
shiny when cut but then quickly reacts and becomes dull
low melting point
Finish the general equation
reactive metal + water –>
remember the fizzing?
reactive metal + water –> metal hydroxide + hydrogen
What is the chemical reaction between lithium and water?
Li (s) + H2O(l) –> LiOH(aq) + H2(g)
Lithium hydroxide is an alkali- it will turn universal indicator blue
What would you observe if you put some sodium in water?
How would this compare to potassium in water?
For sodium
fizzing, moving around on the surface of the water
melts into a ball, metal disappears
For potassium - it is more reactive
more vigorousfizzing
moving around on the surface of the water more quickly
melts into a ball and bursts into flame (lilac in colour)
metal disappears more rapidly
What is the chemical reaction between sodium and water?
Na (s) + H2O(l) –> NaOH(aq) + H2(g)
sodium hydroxide is an alkali- it will turn universal indicator blue
What is the chemical reaction between potassium and water?
K (s) + H2O(l) –> KOH(aq) + H2(g)
potassium hydroxide is an alkali- it will turn universal indicator blue
How would the reaction differ between potassium and rubidium?
Potassium
lilac flame
Rubidium
explosive
What is an alloy?
A mixture of a metal and metal or a metal and non-metal which changes both the physical and chamical properties
Give three examples of an alloy
Brass- copper + zinc
Bronze- copper + tin
Steel- iron + carbon
How does the introduction of a different sized atom to a pure metal change its physical properties.
The smaller atoms disrupts the arrangment of the metal ions,
They no longer arrange themselves in neat rows
They do not have layers which can slide over one another
They are no longer malleable- they are harder and stronger
When calcium reacts with hydorchloric acid, hydrogen forms.
How can the hydrogen be collected?
hydrogen can be collected by downward displacement of water
OR
downward displacement of air - upside down test tube- hydrogen is less dense than air and will rise into the test tube and push the air downward
What are the products in this reaction?
Mg + H2O (g) –>
steam
Mg + H2O (g) –> MgO + H2
steam
with steam the oxide is formed-not the hydroxide!
Both potassium and sodium are found in group 1
Why is potassium more reactive than sodium?
- potassium atom is larger
- outer electrons of potassium are further from the nucleus
- less electrostatic attraction between the negative outer electrons and positive nucleus
- easier to remove the outer electron from potassium
- Also, there are more shells between the nucleus and outer electrons in potassium
- the electrons in these shells repel the outer electrons and is called electron shielding
- easier to remove the outer electron from potassium
- potassium is more reactive for these two reasons!
Complete the reaction
Al + Fe2O3 –>
Thermite reaction!!
Is aluminium more reactive than iron? YES!
2Al + Fe2O3 –> Al2O3 + 2Fe
Aluminiuim is more reactive than iron
aluminium displaces the iron
This is a displacement reaction
Complete this general reaction
metal + steam –>
Metal + steam –> metal oxide + hydrogen
You still get hydrogen but now you have the oxide- not the hydroxide
What is the test for hydrogen gas?
Flaming splint
you hear a squeaky pop!
Why does it take time for aluminium to start reacting with an acid?
aluminium forms an impermeable aluminium oxide layer.
The acid must get through that layer before it comes into contact with the pure metal.
This impermeable oxide layer on aluminium is an advantage- iron reacts with oxygen and rusts entirely through the metal but aluminium forms an impermeable oxide layer protecting the pure aluminium below.
Complete the general word equation
more reactive metal + less reactive metal compound –>
more reactive metal + less reactive metal compound –>
more reactive metal compound + less reactive metal
the more reactive metal displaces the less reactive metal
This is a displacement reaction
Complete the displacement reaction and describe what you would observe
Zn + CuSO4 –>
Is zinc more reactive than copper?
Yes
Zn + CuSO4 –> ZnSO4 + Cu
greysolid & blue solution –> colourless solution & orange/pink soild
Below is the thermite reaction!!
2Al + Fe2O3 –> Al2O3 + 2Fe
Where is this used and is the reaction an exothermic or endothermic reaction? How do you know?
Thermite reaction is used to connect (fuse) iron rails together on a railway.
This reaction is carried out above the seam between the two rails
The reaction is exothermic- it releases heat rapidly and exceed the melting point of iron which melts out the bottom of the vessel and onto the seam.
Complete the displacement reaction and describe what you would observe
Fe + ZnSO4 –>
Is iron more reactive than zinc?
No- the rion cannot displace the zinc
No reaction - grey metal in colourless solution with no change to appearance
Complete the metal displacement reaction
Ca + MgNO3 –>
Ca + 2MgNO3 –> Ca(NO3 )2 + 2Mg
Which reaction will be more vigorous and why?
Mg + Fe2O3 –>
Zn + Fe2O3 –>
The Mg and Fe reaction will be more vigorous because Mg and Fe are further apart in the reactivity series.
The further apart metals are in the reactivity series the more violent their displacement reactions will be.
How can you use metal and acid reactions to order metals in terms of reactivity?
Place the metals in the same concentration and type of acid and compare the rate of fizzing
the more vigorous the fizzing, the more reactive the metal
Define a metallic bond
the electrostatic attractionn between potive metal ions and the negative delocalised electrons
Describe the stuucture of a metal
regular arrangement of metal ions
layers of metal ions surrounded by a sea of delocalised electrons
Why do metals have high melting points?
- many strong metallic bonds in a giant structure
- requires a lot of energy to overcome
als
Are metals soluble in water or organic solvents?
No- they are not soluble in either.
NOTE: reactive metals react with water but they are not soluble
Whjy do metals conduct electricity?
- metals have delocalised electrons which are free to move
and carry charge
Why are metals malleable?
- metal ion layers can slide over one another
- without distrubing the metallic bonds
Which four materials are added to a blast furnace?
iron (III) oxide
limestone
coke
hot air
What are the products from a blast furnace?
iron metal
carbon dioxide
slag
Which product in a blast furnace causes a concern from the environment?
carbon dioxide
is a greenhouse gas which may lead to global warming
Which reaction gets everything hot in the blast furnace?
combustion of coke
C + O2 –> CO2 exothermic!!!
Which reaction forms the reducing agent in the blast furnace?
C + CO2 –> 2CO
coke is added in excess so that CO is formed (carbon monoxide)
carbon monoxide is the reducing agent- it reduces the iron (III) oxide
What is the formula for haematite?
iron (III) oxide
What is the name of iron ore?
Haematite
Complete the redox reaction which happens in the blast furnace
Fe2O3 + 3CO –>
Fe2O3 + 3CO –> 3CO2 + 2Fe
Fe has been reduced - lost oxygen
C is oxidised - gained oxygen
Explain how the reaction below is a redox reaction- a reaction where both oxidation and reduction occurs
Fe2O3 + 3CO –> 3CO2 + 2Fe
Fe2O3 + 3CO –> 3CO2 + 2Fe
Fe has been reduced - lost oxygen
C is oxidised - gained oxygen
Which mnemonic is used to work out which elements are reduced or oxidised in a reacion?
OIL RIG
OIL - oxidation is loss of electrons
RIG - reduction is gain of electrons
REMEMBER: if the atom has gained or lost oxygen you must speak about that and not the gain or loss of electrons
Why do we add limestone to a blast furnace?
To get rid of the impurity found in iron ore
First- the limestone thermally decomposes to calcium oxide because the blast furnace is hot
CaCO3 –> CaO + CO2
The calcium oxide then reacts with the impurity silicon dioxide to form calcium silicate OR SLAG
CaO + SiO2 –> CaSiO3
SLAG
The slag is less dense than the molten iron and float on top
Complete the thermal decomposition of calcium carbonate in a blast furnace
CaCO3 –>
Thermal decomposition means that the compound breaks apart by heating
CaCO3 –> CaO + CO2
Complete the reaction which forms SLAG in a blast furnace
CaO + SiO2 –>
This is a neutralisation reaction
metal oxide CaO - acidic
non-metal oxide SiO2 - alkaline
CaO + SiO2 –> CaSiO3
alkaline + acid –> salt
What is the name of the impurity in haematite?
silicon dioxide
SiO2
What is the chemical formula for SLAG which forms in a blast furnace/
CaSiO3
Why is it easy to separate SLAG from iron metal in a blast furnace?
Both are molten (melted) but the slag is less dense and floats on top of the molten iron
What type of reaction is this?
C + O2 –> CO2
combustion or oxidation as carbon gained oxygen
What type of reaction is this?
CaCO3 –> CaO + CO2
Thermal Decomposition
the CaCO3 is decomposing or breaking apart
What is the reaction for rusting of iron?
4Fe + 3O2 + 5H2O –> 2Fe2O3•5H2O
iron needs both water and oxygen to rust!
Note: salt in not needed but is a catalyst- it speeds up the reaction by lowering hte activation energy but is not used in the reaction
What is the chemical formula for rust?
Fe2O3
What is the chemical name for rust?
iron (III) oxide
Name three barrier methods to stop iron from rusting
paint - to stop oxygen and water getting to iron
coat in plastic- to stop oxygen and water getting to iron
oil or grease- to stop oxygen and water from getting to irion
Name two sacrificial methods to stop iron from rusting
galvanising- coating in zinc- used for buckets etc
sacrificial protection with block of magnesium or zinc- used for bridges or large structures where coating in zinc is too expensive
What is the name of this this protection method for iron?
Fe2O3 + 3Zn –> 3ZnO + 2Fe
sacrificial protection
Zn metal –> Zn 2+ + 2e-
zinc reacts and gives 2 electrons to any iron ions which have formed to reduce it back to iron metal- protecting the iron and sacrificing the zinc
Fe 3+ + 3 e- –> Fe metal
Which metal is being reduced and which one is being oxidised? How do you know?
Fe2O3 + 3Zn –> 3ZnO + 2Fe
Fe2O3 + 3Zn –> 3ZnO + 2Fe
iron is reduced as it is losing oxygen
zinc is oxidised as it is gaining oxygen
Metal carbonates thermally decompose to form a metal oxide and carbon dioxide
Which properties of carbon dioxide prevents us from collecting it by downward displacement of water and allows us to collect it by downward displacement of air?
carbon dioxide is soluble in water- if collected by downward dislacement of water the carbon dioxide would dissolve in the water
carbon dioxide is more dense than air- if a tube was placed in a upright test tube the more dense carbon dioxide would fill the test tube and push the air out.
What is the test for carbon dioxide?
bubble though limewater
limewater turns cloudy
What would you observe in this thermal decomposition reaction?
CuCO3 –> CuO + CO2
green black
green power moves as gas escapes the green powder turns black
Write the thermal decomposition reaction of Copper (II)carbonate
CuCO3 –> CuO + CO2
Complete the reaction for the thermal decomposition of calcium carbonate
CaCO3 –> CaO + CO2
Why can’t we extract aluminium from aluminium ore using coke (carbon)
Carbon is less reactive than Aluminium
it cannot displace aluminium from aluminium ore?
What is the name of aluminium ore?
Bauxite
Al2O3
What method do we use for the extraction of aluminium form aluminium ore?
electrolysis
Define electrolysis
The decomposition of a compound using electricity
Why do we need to melt the aluminium ore before carying our electrolysis?
Aluminium ore is ionic, when melted the metal ions are free to move and carry charge
we need electricity to pass through the molten ore for electrolysis to occur
What is added to aluminium oxide to make the extraction of aluminium cheaper?
Cryolite is added to the aluminium ore- this reduced the melting point of the ore
Less heat is used- cheaper process
Why is electrolysis more expensive than using a blast furnace to extract a metal from its metal ore?
Electrolysis used both electricity and heat to extract the metal.
Blast furnace only needs heat
Which ions are free to move when Al2O3 is melted during electrolysis
Al 3+
O 2-
When aluminium ore is molten the two ions which are mobile are
Al 3+
O 2-
Which ion will move toward the cathode? The negative electrode?
Which ion eill move towards the anode? the positive electrode?
Al 3+ is positively charged and will be attracted to the cathode or negatively charge electrode
O 2- is negatively charged and will be attracted to the anode or positviely charge electrode
Why is the entire container charge negatively in the electrolysis of aluminium ore?
The positive aluminium ions will be attracted to the bottom of the container allowing the aluminium to form there- it can then be tapped off
Why does aluminium oxide conduct when molten (melted) but not when it is a solid?
Aluminium oxide is ionic, when molten the ions are free to move and carry charge
When in the solid form the ions are not free to move and cannot carry charge
Give two properties of carbon dioxide
It is soluble in water to form an acid
It is more dense than air
Use the image below to explain why alloys are less malleable than pure metals
A pure metal will have a regular arrangement of atoms. The rows of metal atoms can slide easily over one another without disrupting the metallic bond
Alloys are a mixture of metals or a metal and non-metal. This often disrupts the regular arrangement. There are no complete rows of atoms which can slide over each other. Not malleable-harder substance
