Reactions of metals

• What happens to metal atoms when they react with other substances?

  They lose electrons to form positive ions.
• What does the reactivity series of metals show?

  It shows metals in order of decreasing reactivity.
• What is generally true about more reactive metals?

  They have more vigorous reactions and lose electrons more easily.
• What are the products when a metal reacts with water?

  • Metal hydroxide
  • Hydrogen gas
• What is the reaction equation for sodium reacting with water?

  2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)
• How does the reactivity of a metal affect its reaction with water?

  The more reactive the metal, the more rapid the reaction.
• What are the products when a metal reacts with a dilute acid?

  • A salt
  • Hydrogen gas
• What is the reaction equation for magnesium reacting with dilute hydrochloric acid?

  Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
• What happens if a metal is below hydrogen in the reactivity series?

  It will not react with dilute acids.
• What do many metals form when they react with oxygen?

  Metal oxides.
• What is the reaction equation for magnesium burning in air?

  2Mg(s) + O2(g) → 2MgO(s)
• Why are the reactions of metals with oxygen classified as oxidation reactions?

  Because the metal gains oxygen.
• In the reaction of copper oxide with carbon, what is oxidized and what is reduced?

  Carbon is oxidized and copper oxide is reduced.
• What is the definition of oxidation in terms of oxygen?

  Oxidation is the gain of oxygen.
• What is the definition of reduction in terms of oxygen?

  Reduction is the loss of oxygen.
• What is a displacement reaction?

  • A more reactive metal displaces a less reactive metal from its compounds.
  • Example: Magnesium displacing copper from copper sulfate solution.
• What is the reaction equation for magnesium displacing copper from copper sulfate solution?

  Mg(s) + CuSO4(aq) → MgSO4(aq) + Cu(s)
• What happens to the blue color of copper sulfate solution during the displacement reaction?

  It fades as it is replaced by colorless magnesium sulfate solution.
• How can a reactivity series be deduced?

  • By carrying out several displacement reactions.
  • Testing different combinations of metal and salt solution.
• What is an ore?

  An ore is a rock that contains enough of a metal or a metal compound to make extraction worthwhile.
• What determines the extraction method used for a metal?

  The metal's position in the reactivity series.
• Why is electrolysis considered expensive for metal extraction?

  Because it requires large amounts of electrical energy.
• What is the reaction equation for copper oxide being reduced by carbon?

  2CuO(s) + C(s) → 2Cu(l) + CO2(g)
• What happens to copper oxide during its reduction with carbon?

  It is reduced as carbon is oxidized.
• What is the reaction equation for the reduction of iron(III) oxide with carbon?

  Fe2O3(s) + 3C(s) → 2Fe(l) + 3CO(g)
• Why is extracting iron cheaper than using electrolysis?

  Because carbon is more reactive than iron and can displace it from its compounds.
• Why must aluminium be extracted using electrolysis?

  Because aluminium is more reactive than carbon.
• What is the role of cryolite in the electrolysis of aluminium oxide?

  • It reduces the melting point of aluminium oxide.
  • It helps to lower costs during the extraction process.
• What happens at the cathode during the electrolysis of aluminium oxide?

  Aluminium ions gain electrons and form aluminium atoms.
• What happens at the anode during the electrolysis of aluminium oxide?

  Oxide ions lose electrons and form oxygen gas.
• What is the half equation for the oxidation of oxide ions during electrolysis?

  2O^{2-} → O_2 + 4e^{-}
• What is the significance of the acronym OIL RIG in redox reactions?

  • OIL: Oxidation Is Loss of electrons.
  • RIG: Reduction Is Gain of electrons.