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Transcript of Displacement reactions - cgrahamphysics.files.wordpress.com · A displacement reaction happens when...
Displacement reactions
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Starter: match them up
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Elements for speed dating
Hydrogen
Oxygen
Carbon
Sodium Magnesium
Chlorine
Helium Fluorine Potassium Calcium
Sulphur
Bromine Iron copper Zinc
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Speed dating • Interactive periodic table
• You will draw an element. You have 4 minutes to fill out your dating sheet with information
• Metals will stay seated. Non Metals will move around and try to catch a “date”
• Write down your combined name
• Decide by the end of the class if your combination is possible
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Aim • Be able to use displacement reactions to
deduce the position of a metal within the
reactivity series
Key words
• Reactivity
• Displacement reaction 치환반응
• Reactivity series 연쇄 반응
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The big picture
Can you predict when a displacement reaction will occur?
Have you ever wondered 17/05/2016 ©cgrahamphysics.com 2016
Recap: the reactivity series
potassium sodium lithium calcium
magnesium aluminium
zinc iron
copper silver gold
most reactive
least reactive
K Na Li Ca Mg Al Zn Fe Cu Ag Au
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9F Feeling a bit displaced?
A displacement reaction happens
when one metal replaces another
one in a compound.
Magnesium is more reactive
than copper.
magnesium + copper sulphate magnesium sulphate
+ copper
Magnesium displaces copper from copper sulphate solution, e.g.
Displacement Reactions
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Cartoon displacement
Mr Sulphate Miss Iron
Iron sulphate
Miss Zinc +
+ Zinc
Miss Zinc
Zinc Sulphate + Iron
Mr Sulphate Miss Iron
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9F A model for displacement reactions
Displacement Reactions
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• If a more reactive metal is placed into one of these metal solutions it will react and displace the other metal
• For example the reaction between copper sulphate and magnesium
Copper sulphate (blue)
Magnesium Magnesium Sulphate (clear)
Copper
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The copper in the copper
sulphate is turning into
red copper metal.
Displacement Reactions
• Reaction between copper sulphate and magnesium.
• Why does the blue copper sulphate colour gradually disappear?
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Mg
Magnesium
SO4 Cu
Copper sulphate
The magnesium
DISPLACES the copper
from copper sulphate
SO4 Mg
Magnesium sulphate
Cu
Copper
Magnesium + copper sulphate magnesium sulphate + copper
Displacement reactions
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Your Experiment
• You have been given the following:
copper copper sulfate solution
iron iron sulfate solution
magnesium magnesium sulfate solution silver silver nitrate solution
• Organise a series of experiments to determine the order of reactivity for all 4 metals
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Table
Magnesium Iron Copper Silver
Magnesium sulfate solution
Iron sulfate solution
Copper sulfate solution
Silver nitrate solution
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1) When steel wool is placed in copper sulphate solution, the wool turns into a pink powder and the solution goes from blue to yellow in colour. Steel is a form of iron. Explain this observation
2) Mercury is an unreactive metal, below copper in the reactivity series. It is highly toxic. Jo placed some zinc metal into a beaker of mercury chloride solution. She noticed small silver beads appearing at the bottom of the beaker. Explain this observation using a word/symbol equation.
3) Explain how you could extract silver metal from a solution of silver nitrate using the idea of metal displacement reactions.
4) Paul was given some tin metal, tin chloride solution, lead metal and lead nitrate solution. Describe how Paul would be able to work out whether tin or lead is the more reactive metal.
Answer these questions in your book
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copper + magnesium sulphate
copper sulphate
+ magnesium
zinc + magnesium sulphate
zinc sulphate + magnesium
iron + magnesium sulphate
iron sulphate + magnesium
Magnesium
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No reaction magnesium sulphate
+ Zinc
iron + zinc sulphate iron sulphate + Zinc
copper + zinc sulphate copper sulphate
+ Zinc
Zinc
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No reaction magnesium sulphate
+ copper
No reaction zinc sulphate + copper
No reaction copper sulphate
+ copper
Copper
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No reaction magnesium sulphate
+ iron
No reaction zinc sulphate + iron
copper + iron sulphate copper sulphate
+ iron
Iron
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Plenary
Hydrogen
Oxygen
Carbon
Sodium Magnesium
Chlorine
Helium Fluorine Potassium Calcium
Sulphur
Bromine Iron copper Zinc
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• Look back at the combinations you formed at the beginning • Which element can steal the non metal from your compound?
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Plenary: Questions
Look at this table and answer all questions on the sheet
Mg Fe Zn Mg
ZnSO4 CuSO4 FeSO4 CuSO4
silvercoloured
darkgrey
lightgrey
silvercoloured
colour ofmetal at start
colour ofsolution at
start
appearenceof metal at
end
colour ofsolution at
end
colourless
light grey
colourless
pale blue
brown
palegreen
pale green
colourless
pale blue
diagram ofexperiment
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Key words • Reactivity - the tendency of a substance to undergo a chemical reaction, either by itself or with other materials, and to release energy.
• Displacement reaction – a reaction in which a more reactive element displaces a less reactive element from its compound.
• Reactivity series – an analytical progression of a series of metals, arranged by their "reactivity" from highest to lowest.
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