chemical reactions

• Oxidation


  When a metal reacts with oxygen, the metal has gained oxygen
• Reduction


  When oxygen is removed from a metal compound, the metal atoms have lost oxygen
• Reaction of metals with oxygen

  1. Form metal oxide

  2. Oxidation reaction occurs
• Reactions of metals with oxygen

  • Magnesium reacting with oxygen
  • Iron reacting with oxygen
• Magnesium reacting with oxygen

  Rapid reaction, releases heat and light
• Iron reacting with oxygen

  Slow reaction, takes weeks or months
• When metals react with oxygen, we form metal oxides
• In the reaction between calcium and copper oxide, calcium is oxidized and copper is reduced
• More questions on reactions of metals with oxygen and oxidation/reduction can be found in the revision workbook
• Reactivity series


  A series that shows the reactivity of different metals, determined by their reactions with water and acids
• Determining reactivity of metals

  1. React metals with water

  2. React metals with dilute acids

  3. Observe rate of reaction
• Metals in order of decreasing reactivity

  • Potassium
  • Sodium
  • Lithium
  • Calcium
  • Magnesium
  • Zinc
  • Iron
  • Copper
• Potassium, sodium, and lithium react very rapidly with water
• Calcium reacts quite rapidly with water
• Magnesium, zinc, iron, and copper have no reaction with water at room temperature
• Potassium, sodium, and lithium react too vigorously with dilute acids to be tested safely
• Metals in order of decreasing reactivity with dilute acids

  • Calcium
  • Magnesium
  • Zinc
  • Iron
  • Copper
• Metals at the top of the reactivity series readily form positive ions
• Metals at the bottom of the reactivity series are much less likely to form positive ions
• Carbon and hydrogen are also included in the reactivity series, though you are not expected to memorize the full series
• Acids


  Hydrochloric acid, sulfuric acid, nitric acid
• All acids contain hydrogen
• Metals more reactive than hydrogen


  Can displace hydrogen from acids
• Reaction between sulfuric acid and magnesium

  1. Magnesium displaces hydrogen

  2. Produces magnesium sulfate and hydrogen gas
• Salt


  Product when acids react with metals
• Salts produced


  • Hydrochloric acid produces salts ending in chloride
  • Sulfuric acid produces salts ending in sulfate
• Reaction of magnesium with hydrochloric acid

  Produces magnesium chloride and hydrogen gas
• Reaction of magnesium with sulfuric acid

  Produces magnesium sulfate and hydrogen gas
• Magnesium is highly reactive


  Can easily displace hydrogen from acids
• Reaction of zinc with hydrochloric acid

  Produces zinc chloride and hydrogen gas
• Reaction of zinc with sulfuric acid

  Produces zinc sulfate and hydrogen gas
• Zinc is highly reactive


  Can easily displace hydrogen from acids
• Reaction of iron with hydrochloric acid

  Produces iron chloride and hydrogen gas
• Reaction of iron with sulfuric acid


  Produces iron sulfate and hydrogen gas
• Iron is slightly more reactive than hydrogen


  Reaction with acids is slow
• You'll find plenty of questions on the reactions of acids with metals in the revision workbook
• Acid


  A chemical that can neutralize a base and produce a salt and water
• Base


  A chemical that can neutralize an acid and produce a salt and water
• Alkali


  A soluble base that can be dissolved in water
• Reaction between an acid and a base/alkali


  Produces a salt and water