SPM Form 5: Oxidation and Reduction (Checklist)
- Oxidation: A reaction that
occurs when a substance gains oxygen.
- Oxidizing agent: The
substance that oxidizes other reacting substances in a reaction while it is
being reduced.
- Reduction: The reaction that
occurs when a substances loses oxygen.
- Reducing agent: The
substance that reduces other reacting substances in a reaction in a reaction
while it is being oxidized.
- Redox reaction: A chemical
reaction in which oxidation and reduction occur simultaneously.
- Metal displacement reaction:
A reaction where a more electropositive metal replaces a less electropositive
metal from its salt solution. In a metal displacement reaction, a more
electropositive metal acts as the reducing agent whereas the ion of the less
electropositive metal in the salt solution acts as the oxidizing agent.
- Halogen displacement
reaction: A reaction where a more reaction halogen replaces a less reactive
halogen from its halide solution. In a halogen displacement reaction, a more
reactive halogen acts as the oxidizing agent whereas the halide ion of the less
reactive halogen acts as the reducing agent.
- Rusting of iron = the
corrosion of ion. Rusting can be
prevented when iron is in contact with a more electropositive metal. Rusting
occurs faster when iron is in contact with a less electropositive metal.
- Reactivity series of metals:
A list of metal that are arranged according to their reactivity with oxygen.
The descending order of reactivity of metal with oxygen is magnesium, zinc,
iron, lead and copper.
- Carbon is placed between
aluminium and zinc in the reactivity series. Magnesium is placed higher than
carbon in the reactivity series. Carbon acted as a reducing agent because the
metal oxide was reduced to metal in the presence of carbon.
- Hydrogen is placed between
zinc and iron in the reactivity series. Hydrogen gas acted as a reducing agent
because the metal oxide was reduced to metal in the presence of hydrogen gas.
- In an electrolytic cell,
oxidation takes place at the anode whereas reduction takes place at the
cathode.
- In a chemical cell,
oxidation takes place at the negative terminal (anode) whereas reduction takes place at the positive terminal (cathode).
