Reactivity with metals
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Transcript of Reactivity with metals
12/04/23
Reactivity of MetalsReactivity of Metals
12/04/23Reactions of metals with Reactions of metals with oxygenoxygen
When a metal reacts with oxygen it will form a METAL OXIDE. This is what happens when a metal rusts. We can make this reaction happen quicker by burning the metal.
METAL + OXYGEN METAL OXIDE
Copy and complete the following reactions:
1) Magnesium + oxygen
2) Copper + oxygen
3) Calcium + oxygen
4) Iron + oxygen
12/04/23Reactions of metals with Reactions of metals with waterwater
When a metal reacts with water hydrogen is always given off. The other product will be either a metal hydroxide or a metal oxide.
Copy and complete the following reactions:
1) Sodium + water
2) Potassium + water
3) Calcium + water
4) Iron + steam
METAL + WATER METAL OXIDE + HYDROGEN
METAL + WATER METAL HYDROXIDE + HYDROGEN
12/04/23Reactions of metals with Reactions of metals with acidsacids
When a metal reacts with an acid it gives off hydrogen (which can be “popped” using a lit splint). The other product is a salt.
Copy and complete the following reactions:
1) Calcium + hydrochloric acid
2) Zinc + hydrochloric acid
3) Iron + hydrochloric acid
4) Lithium + sulphuric acid
METAL + ACID SALT + HYDROGEN
e.g. magnesium + hydrochloric acid magnesium chloride + hydrogen
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Complete the following reactions:Complete the following reactions:
1) Lithium + water
2) Lithium + hydrochloric acid
3) Silver + oxygen
4) Magnesium + sulphuric acid
5) Potassium + oxygen
6) Aluminium + oxygen
7) Manganese + water
8) Sodium + sulphuric acid
9) Lithium + oxygen
10)Nickel + hydrochloric acid
Lithium hydroxide + hydrogen
Lithium chloride + hydrogen
Silver oxide
Magnesium sulphate + hydrogen
Potassium oxide
Aluminium oxide
Manganese oxide + hydrogen
Sodium sulphate + hydrogen
Lithium oxide
Nickel chloride + hydrogen
12/04/23An example question on An example question on reactivityreactivity
Metal Reaction with dilute
acid
Reaction with water
Reaction with
oxygen
ASome reaction Slow reaction Burns
brightly
B No reaction No reaction Reacts slowly
C No reaction No reaction No reaction
DViolent reaction
Slow reaction Burns brightly
EReasonable reaction
Reacts with steam only
Reacts slowly
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The Reactivity SeriesThe Reactivity Series
The Reactivity Series lists metals in order of reactivity:
Potassium
Sodium
Calcium
Magnesium
Aluminium
Carbon
Zinc
Iron
Lead
Copper
Silver
Gold
12/04/23Displacement reactionsDisplacement reactions
Mg
Magnesium
SO4Cu
Copper sulphate
The magnesium DISPLACES the copper from copper sulphate
SO4Mg
Magnesium sulphate
Cu
Copper
A displacement reaction is one where a MORE REACTIVE metal will DISPLACE a LESS REACTIVE metal from a compound.
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Displacement reactionsDisplacement reactions
A displacement reaction is one where a MORE REACTIVE metal will DISPLACE a LESS REACTIVE metal from a compound.
For example, if you drop some magnesium into copper sulphate a reaction will happen because magnesium is more reactive than copper, so the reaction is:
Magnesium + copper sulphate copper + magnesium sulphate
However, if you drop some copper into magnesium sulphate NOTHING will happen.
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Some example reactions…Some example reactions…
Reaction Prediction Observations
Zinc + copper sulphate
Zinc + lead nitrate
Copper + lead nitrate
Copper + silver nitrate
Extension work – write down the equations for these reactions
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Some example reactions…Some example reactions…
Reaction Prediction Observations
Zinc + copper sulphate
Reaction DID happen
Zinc + lead nitrate Reaction DID happen
Copper + lead nitrate
Reaction DID NOT happen
Copper + silver nitrate
Reaction DID happen
Extension work – write down the equations for these reactions
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Extracting MetalsExtracting Metals
Some definitions:
A METAL ORE is a mineral or mixture of minerals from which it is “economically practical” to extract some metal.
Most ores contain METAL OXIDES (e.g. rust = iron oxide).
To “extract” a metal from a metal oxide we need to REDUCE the oxygen. This is called a REDUCTION reaction.
12/04/23How do we do it?How do we do it?Potassium
Sodium
Calcium
Magnesium
Aluminium
Carbon
Zinc
Iron
Tin
Lead
Copper
Silver
Gold
Platinum
Metals ABOVE CARBON, because of their high reactivity, are extracted by ELECTROLYSIS
Metals BELOW CARBON are extracted by heating them with carbon in a BLAST FURNACE
These LOW REACTIVITY metals blatantly won’t need to be extracted because they are SO unreactive you’ll find them on their own, not in a metal oxide
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Extracting metalsExtracting metals
1) What is an ore?
2) In what form are metals usually found in the Earth?
3) How do you get a metal out of a metal oxide?
4) What is this type of reaction called?
Type of metal Extraction process
Examples
High reactivity (i.e anything above
carbon)
Middle reactivity (i.e. anything below
carbon)
Low reactivity
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The Blast FurnaceThe Blast Furnace1) HAEMATITE (iron ore), limestone and coke (carbon) are fed in here
2) Hot air is blasted in here
3) The carbon reacts with oxygen from the air to form carbon dioxide.
4) The carbon dioxide reacts with more carbon to form carbon monoxide
6) Molten slag (waste) is tapped off here
5) Carbon monoxide reduces iron oxide to iron. The molten iron is tapped off here
Iron oxide + carbon monoxide iron + carbon dioxide
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ElectrolysisElectrolysis
Molecule of solid copper chloride
Molecule of solid copper chloride after being dissolved
Chloride ion
Copper ion
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ElectrolysisElectrolysisElectrolysis is used to extract a HIGHLY REACTIVE metal.
= chloride ion
= copper ion
When we electrolysed copper chloride the
negative chloride ions moved to the positive
electrode and the positive copper ions
moved to the negative electrode – OPPOSITES
ATTRACT!!!
12/04/23Redox reactionsRedox reactionsThese happen during electrolysis:
These two processes are called REDOX REACTIONS
OILRIG – Oxidation Is Loss of electrons
Reduction Is Gain of electrons
At the positive electrode the negative ions LOSE electrons to
become neutral – this is OXIDATION
At the negative electrode the positive ions GAIN electrons to
become neutral – this is REDUCTION
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Purifying Purifying AluminiuAluminiu
mm
Aluminium has to be extracted from its ore (called ________) by electrolysis. This is because aluminium is very ___________. The ore is mixed with cryolite to lower its ________ ________. The ore is then melted so that the ions can ______. The positively charged aluminium ions gather at the ___________ electrode. Oxygen forms at the positive electrode and causes it to wear away, which means that they have to be __________ frequently.
Words – melting point, replaced, negative, bauxite, reactive, move
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Rusting ExperimentRusting Experiment
RUST NO RUST – no water
NO RUST – no oxygen
12/04/23RustingRustingRust is formed when iron reacts with water AND
oxygen. It’s an example of an oxidation reaction which can be sped up using salt. There are several ways of dealing with rust:
1) Regular painting or oiling
2) Galvanising – this is when iron objects are coated with zinc
3) Making objects out of a non-rusting metal, such as stainless steel
4) Attaching zinc bars to ships – the water will react with the zinc before it reacts with the iron, because zinc is more reactive