Reactivity Series

• What are the products when a reactive metal reacts with cold water?

  Metal hydroxide and hydrogen gas
• Why does potassium react with cold water to form potassium hydroxide and hydrogen gas?

  Because potassium is a very reactive metal
• What is the general reaction between a metal and an acid?

  Metal + acid → salt + hydrogen
• Why does gold not react with water, acid, or oxygen?

  Because gold is extremely unreactive
• What is the product when a metal reacts with oxygen?

  Metal oxide
• How can the relative reactivity of metals be deduced?

  By observing their reactions with water, acid, and oxygen
• What is a displacement reaction in the context of metals?

  A more reactive metal displaces a less reactive metal from its compound
• What happens to the more reactive metal in a displacement reaction?

  It gradually disappears as it forms a solution
• What is the order of reactivity for the following metals: potassium, sodium, lithium, calcium, magnesium, aluminium, zinc, iron, copper, silver, gold?


  Potassium, sodium, lithium, calcium, magnesium, aluminium, zinc, iron, copper, silver, gold
• Why is the reactivity of a metal related to its tendency to form positive ions?

  Because more reactive metals lose electrons more easily to form positive ions
• What are the conditions necessary for iron to rust?

  Air and water
• How does painting prevent iron from rusting?

  It excludes oxygen and water
• What is sacrificial protection in the context of preventing rust?

  Using a more reactive metal to protect iron from rusting
• Why is zinc used to galvanise iron?

  Because zinc is more reactive and will rust first
• What is oxidation in terms of electron transfer?

  Loss of electrons
• What is the role of an oxidising agent in a redox reaction?

  It causes another reactant to be oxidised and is reduced itself
• What is the general reaction between a metal and a dilute acid?

  Metal + acid → hydrogen + salt
• Why do more reactive metals give off more hydrogen gas when reacting with acids?

  Because they lose electrons more easily to form hydrogen gas
• What are the methods to prevent iron from rusting?

  • Barrier methods (painting, coating with plastic, using oil or grease)
  • Galvanising (coating with a more reactive metal like zinc)
  • Sacrificial protection (using a more reactive metal to rust first)
• What are the key terms in redox reactions?

  • Oxidation: gain of oxygen or loss of electrons
  • Reduction: loss of oxygen or gain of electrons
  • Redox: reaction where both oxidation and reduction occur
  • Oxidising agent: causes oxidation and is reduced itself
  • Reducing agent: causes reduction and is oxidised itself
• What are the observations when metals react with acids?

  • More reactive metals give off large amounts of H2 gas bubbles
  • Less reactive metals give off little to no H2 gas
  • The metal gradually disappears as it forms a solution