Group 2

• How does the size of the atoms change going down the group?

  Atoms get bigger going down the group because each element has one more shell than the element before it.
• What happens to the atomic radii as each atom gains a shell of electrons?

  The atomic radii increases
• How do melting points change going down the group?

  Melting points decrease slightly down the group
• Why do melting points decrease down the group?

  Metallic bonds weaken as electrons are further from nuclei
• How do ionisation energies change going down the group?

  First and second ionisation energies decrease
• Why does it take less energy to remove outermost electrons going down the group?

  Atomic radii and shielding effects increase due to increasing number of shells
• What is the pattern of reactivity going down the group?

  They get more reactive going down the group due to increasing atomic radius
• What is the change in oxidation state for group 2 metals during reactions?

  0 to +2, they are oxidised
• What products are formed when a group 2 metal reacts with water?

  Metal hydroxide and hydrogen
• How does magnesium react with warm water?

  They react slowly with cold water
• What products are formed when a group 2 metal reacts with steam?

  Metal oxide and hydrogen
• How does magnesium react with steam?

  They react rapidly with steam
• How does the solubility of metal hydroxides change going down the group?

  They become more soluble going down the group
• How does the solubility of metal sulfates change going down the group?

  They become less soluble going down the group
• What is a medical use of magnesium hydroxide?

  It is used as a laxative
• What is a use of barium sulfate?

  Used to produce an X-ray image
• What substance is used to reduce titanium chloride?

  Magnesium is the reducing agent
• How do we use magnesium to extract titanium from titanium oxide?

  • Titanium oxide is reacted with chlorine and carbon dioxide to form TiCl4 and carbon monoxide
  • Titanium chloride is then reduced to Ti in a reaction with magnesium:
  • TiCl4 (l) + 2Mg (s) --> 2MgCl2 (s) + Ti (s)
• Magnesium hydroxide is....insoluble


  Sparingly
• How do we use Ca(OH)2 in agriculture?


  It is used to treat acidic soil
• BaSO4 is....


  Insoluble
• Why is acidified BaCl2 solution used to test for sulfate ions?

  • Sulfate ions displace chloride ions
  • Acidified to remove any carbonate ion impurities
• Is there a flame in mg reaction with steam?


  Yes, bright white flame
• Is there a flame in Mg reaction with warm water?

  No
• Why must we clean magnesium ribbon?

  It will have a layer of magnesium oxide on top
• What would we observe in the reactions of the group 2 metals with cold water down the group?

  • Fizzing (more vigorous)
  • Metal dissolving (faster down group)
  • Solution heating up (more down group)
  • White precipitate forms with calcium (hydroxide less soluble)
• Why is titanium useful?

  Abundant

  Low density

  Corrosion resistant
• Why can titanium not be extracted with CO2?

  Would form titanium carbide rather than titanium
• Why is titanium expensive?

  • Expensive cost of Mg
  • Batch process, slower
  • Argon needed
  • High temperatures
• Why does alkalinity of hydroxides increase down group?


  More soluble down group, more hydroxide ions present in solution