Reactivity series

• Reactivity series:

  Potassium - Reacts with water and acid

  Sodium - Reacts with water and acid

  Lithium - Reacts with water and acid

  Calcium - Reacts with water and acid

  Magnesium - reacts with acid

  Aluminium - reacts with acid

  Zinc - reacts with acid

  Iron - reacts with acid

  Copper

  Silver

  Gold
• A metal will displace another metal from its oxide that is lower in the reactivity series. For example, a reaction with magnesium and copper (II) oxide will result in the magnesium displacing the copper from its oxide:

  A metal will also displace another metal from its salt that is lower in the reactivity series. For example, the reaction between zinc and copper (II) sulfate solution will result in zinc displacing the copper from its salt:

  The blue colour of the copper (II) sulfate solution fades as colourless zinc sulfate solution is formed.
• Iron rusts when oxygen and water are present
• Barrier Methods: Rusting may be prevented by stopping the water and oxygen getting to the iron with a barrier of grease, oil, paint or plastic.
• Galvanising: (coating in zinc) also prevents water and oxygen getting to the iron, but with galvanising even if the barrier is broken the more reactive zinc corrodes before the less reactive iron. During the process, the zinc loses electrons to form zinc ions.
• Sacrificial Protection: Zinc blocks are attached to iron boat hulls and underground pipelines to act as sacrificial anodes. Zinc is more reactive than iron, so oxygen in the air reacts with the zinc to form a layer of zinc oxide instead of the iron.
• Oxidation

  • Oxidation is the loss of electrons. For example a sodium atom (Na) loses an electron to become a sodium ion (Na⁺). Another example is a chloride ion (Cl⁻) losing an electron to become a chlorine atom (Cl).
  • Another definition of oxidation is the gain of oxygen. For example if carbon combines with oxygen to form carbon dioxide, the carbon is being oxidised.

   
• Reduction

  • Reduction is the gain of electrons. For example a sodium ion (Na⁺) gains an electron to become a sodium atom (Na). Another example is a chlorine atom (Cl) gaining an electron to become a chloride ion (Cl⁻).
  • Another definition of reduction is the loss of oxygen. For example when aluminium oxide is broken down to produce aluminium and oxygen, the aluminium is being reduced.
• Redox: A reaction involving oxidation and reduction.
• Oxidising agent: A substance that gives oxygen or removes electrons (it is itself reduced).
• Reducing agent: A substance that takes oxygen or gives electrons (it is itself oxidised).
• Which metals react with dilute hydrochloric or sulfuric acid?

  Metals above hydrogen in reactivity series
• What is produced when metals react with acids?

  A salt and hydrogen gas
• Write the general reaction for a metal reacting with an acid.

  Metal + Acid → Salt + Hydrogen
• What is the product of magnesium reacting with hydrochloric acid?

  Magnesium chloride and hydrogen
• What does the equation Mg + 2HCl → MgCl₂ + H₂ represent?

  Magnesium reacting with hydrochloric acid
• What type of reaction is represented by the equation Mg + 2HCl → MgCl₂ + H₂?

  Displacement reaction
• What observable effect occurs during the reaction of magnesium with acid?

  Rapid fizzing and colorless gas production
• What does the popping sound with a lighted splint indicate?

  The gas produced is hydrogen
• What happens to the temperature of the reaction mixture?

  It becomes warm due to heat production
• What happens to magnesium during the reaction with acid?

  It disappears, leaving a colorless solution
• How does the reactivity of metals affect the reaction rate with acids?

  More reactive metals react faster and fizz more
• What is the effect of using more reactive metals instead of magnesium?

  The reaction will be faster and more vigorous