Reactivity of Metals

• Metal oxides

  • metals react with oxygen to produce metal oxides
• Oxidation

  • metals gain oxygen
  • loss of electrons
• OILRIG

  Oxidation - loss of electrons

  Reduction - gain of electrons
• Metals reactions

  • When metals react with other substances, the metal atom loses electrons to form positive ions
• What does the reactivity of a metal depend on?

  • tendency to lose electrons + form positive ions
• What do you expect to see when magnesium reacts with water?

  • magnesium disappears
  • fizzing - indication of hydrogen gas produced
• Displacement reactions

  • a more reactive metal can displace a less reactive metal
• Copper oxide + calcium --> ______ + ________?

  • calcium oxide + copper

  calcium displaces copper because calcium is more reactive than copper
• Copper can be extracted from solutions of copper salts by adding iron. Explain why.

  • iron is more reactive (than copper)
  • so copper is displaced
• When a metal reacts with water

  • a hydroxide is formed
  • hydrogen gas is formed
  • fizzing occurs
  • metal will disappear / dissolve
• Non-metals hydrogen and carbon are included. Why?

  • to compare reactivity
• Reactivity Series

  • Based on tendency to for a metal to lose electrons and form positive ions

  
• Unreactive metals are found

  • Found on earth
  • The metal itself
• Most (more reactive) metals are found in..

  • ores
  • require chemical reactions to extract the metal
• Reactivity series : Metals less reactive than carbon 


  • Can be extracted from their oxides by reduction with carbon
• Zinc oxide + carbon --> _____ + ______?

  • carbon dioxide
  • zinc

  Zinc is displaced by carbon as carbon is more reactive than zinc
• What is special about ores?

  • Impure
• Example of unreactive metal found by itself

  • Gold
• Investigating reactivity with metals :

  • Acid
  • Water
• With acids

  • Metal + acid --> salt + hydrogen
  • Measure the rate of hydrogen bubble production
  • The faster the reaction, the greater bubble production of hydrogen per minute
• Very reactive metals

  • Vigorous
  • Explosion
• Less reactive metals

  • Less violent
• How to detect production of hydrogen gas?

  • use of a burning splint
  • place burning splint at mouth of test tube
  • If present, squeaky pop
  • The more reactive, the louder the squeaky pop
• What would you expect to see Magnesium VS Zinc when both reacted with hydrochloric acid?

  • Greater bubble production of hydrogen with magnesium per minute in comparison to zinc.
  • Louder squeaky pop with magnesium.
  • Therefore, magnesium is more reactive than zinc.
• Metal + water

  • metal hydroxide + hydrogen
• Displacement reaction : A less reactive metal reacting with a more reactive metal 


  • Will not displace the more reactive metal because it is less reactive.
  • No reaction happens.
• Define a metal ore

  • Rock that contains enough metal to make it profitable to extract a metal from it.
• Most ores form

  • metal oxides
• Extraction of metals by reduction with carbon

  • Can only happen with metals that are less reactive than carbon in the reactivity series.
• Describe reduction by carbon

  • The ore is reduced as oxygen is removed from it.
  • Carbon gains oxygen as it is oxidised to form carbon dioxide.
• For example : Iron (III) oxide is reduced in a blast furnace to make iron

  Iron oxide + carbon --> carbon dioxide + iron

  2Fe2O3 + 3C --> 4Fe + 3CO2
• Examples of metals that are reduced by carbon :

  • Zinc
  • Iron
  • Copper
• When investigating the reactivity of metals against other metals, with acid or water : Control variable

  • Volume of acid / water
  • Mass of metal
  • Temperature of acid / water
• Inaccuracies may be caused by not :

  • Stirring
• The student is provided with:

  • silver nitrate solution

  • metal Q powder

  • zinc powder

  • a thermometer

  • normal laboratory equipment.

  Describe a method the student could use to compare the reactivity of metal Q with that of zinc.

  • measure temperature change
  • when each metal is added to silver nitrate solution
  • same concentration / volume of solution
  • the greater the temperature change the more reactive
• The greater the temperature change..

  • the more reactive the metal is
• Copper reaction with acid

  • Copper does not react with dilute hydrochloric acid.
  • No temperature change / no bubbles
• Compare temperature change with magnesium and zinc

  • Magnesium increases in temperature more than zinc