Reactivity Series of Metals

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Reactivity Series of Metals

• Reactions of Metals
• Effect of Heat on Metal Carbonates

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Reactivity Series of Metals

• Chemical Properties of Metals
• Metal reaction with cold water steam
• Metal reaction with hydrochloric acid
• Reaction of Metals Displacement Reactions
• With aqueous ions of another metal
• With the oxide of another metal
• Reaction of Metal Oxides
• With carbon
• With hydrogen
• Effect of Heat on Metal Carbonates
• Thermal stability reactivity

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Recap Chemical Properties of Metals

• Reaction with Water (Cold Water)
• Metal Cold Water ? Metal Hydroxide Hydrogen
  Gas
• Eg. 2Na(s) 2H2O(l) ? 2NaOH(aq) H2(g)
• Which are some metals that react with cold water?

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Recap Chemical Properties of Metals

• Reaction with Water (Steam)
• Metal Steam ? Metal Oxide Hydrogen Gas
• Eg. Mg(s) H2O(g) ? MgO(s) H2(g)
• Which metals only react with steam?

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Recap Chemical Properties of Metals

• Reaction with Hydrochloric Acid
• Metal Hydrochloric Acid ? Salt Hydrogen Gas
• Eg. 2K(s) 2HCl(l) ? 2KCl(aq) H2(g)
• The more vigorous the reaction
• The higher it is in the reactivity series
• The more reactive is the metal

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Reaction of Metals With the Aqueous Ions of
Another Metal

• Displacement of metals from solution
• More reactive metals can displace less reactive
  metals from their salt solutions.
• This can be used to find the position of metals
  in the reactivity series.

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Iron Nail in Copper(II) Sulphate Solution

• Observations
• Reddish-brown solid forms on the surface of the
  iron nail
• Blue solution becomes pale green
• Fe (s) CuSO4 (aq) ? FeSO4 (aq)
  Cu (s)

Copper(II) Sulphate Solution
Iron(II) Sulphate Solution
Iron
Copper
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Iron Nail in Copper(II) Sulphate Solution

• Brown solid Copper metal
• Solution turns pale green
• Copper has been removed from the solution.
• Iron(II) sulphate solution is pale green in
  colour.
• We say that
• Iron has displaced copper from the copper(II)
  sulphate solution.

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Think!

• What will happen when
• a piece of magnesium strip is immersed in
• a solution of copper(II) sulphate?

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Some Possible Observations

• Deposit of the more reactive metal (from its
  aqueous solution)
• Colour of the solution may change
• Heat may be given off

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Displacement Reactions are Redox Reactions

• The more reactive metal is oxidized
• The less reactive metal is reduced
• For example,
• Chemical Equation
• Fe (s) CuSO4 (aq) ? FeSO4 (aq) Cu (s)
• Ionic Equation
• Fe (s) Cu2 (aq) ? Fe2 (aq) Cu (s)

REDOX reaction!
Copper(II) ions are reduced to become copper atoms
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Displacement Reactions are Redox Reactions

• A more reactive metal
• readily gives up electrons in reactions
• has greater tendency to form positive ions
• As a result
• A more reactive metal can displace
• a less reactive metal,
• from its solution or metallic oxide.

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Reaction of Metals With the Oxide of Another
Metal

• Displacement of metals from metallic oxides
• A more reactive metal can reduce the oxide of a
  less reactive metal.
• For example Thermit reaction
• 2Al (s) Fe2O3 (s) ? Al2O3 (s) 2Fe (l)

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Reaction of Metals With the Oxide of Another
Metal

• Thermit Reaction
• 2Al (s) Fe2O3 (s) ? Al2O3 (s) 2Fe (l)
• The more reactive the metal is, the more readily
  it forms compounds.
• Unreactive metals tend to stay umcombined.

Aluminium atoms are oxidized to become
aluminium(III) ions
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Reaction of Metal Oxides With Carbon

• Carbon can remove oxygen from the oxides of
  metals that are not too high up in the Reactivity
  Series.
• The lower the position of a metal in the
  Reactivity Series, the easier it is for carbon to
  remove oxygen from the metal oxide.

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Reaction of Metal Oxides With Carbon
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The Importance! Reaction of Metal Oxides With
Carbon

• metals need to be extracted from their ores
  before we can use them
• metals below magnesium are often extracted from
  their ores by reduction with carbon (WHY?)
• metals above zinc cannot be extracted by
  reduction with carbon bc they are stable (THEN
  WHAT?)

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Reaction of Metal Oxides With Hydrogen

• Hydrogen can remove oxygen from metallic oxides,
  producing the metal and water(steam).
• metal oxide hydrogen ? metal steam
• The lower the position of a metal in the
  Reactivity Series, the easier it is for hydrogen
  to remove oxygen from the metal oxide.

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Reaction of Metal Oxides With Hydrogen
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Effect of Heat on Metal CarbonatesThermal
Stability Reactivity

• Most carbonates decompose when heated strongly to
  produce a metal oxide and carbon dioxide gas.
• The ease of decomposition depends on the
  position of the metal in the reactivity series.
• Recall the reactivity series.

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Thermal Stability of Metal Carbonates
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• Reactions with water dilute acids
• More vigorous reaction
• ? Higher in the reactivity series
• ? The metal is more reactive
• Reaction with metal carbonates
• The more stable the metal carbonate is to heat,
  the higher it is in the reactivity series.

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Class Activity Discussion

• Check this out!
• http//www.chem.iastate.edu/group/Greenbowe/secti
  ons/projectfolder/flashfiles/redox/home.html

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So, what have you learnt today?

• Displacement Reaction
• They are redox reactions.
• A more reactive metal can displace a less
  reactive metal, from its solution or metallic
  oxide.
• Carbonates Thermal stability reactivity
• The more stable the metal carbonate is to heat,
  the higher it is in the reactivity series.

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