Group 2

• Trend in atomic radius down group 2

  • Increases
  • More shells present
• Trend in reactivity down group 2

  • Increases
  • Negative outer electrons further from positive nucleus so it is easier for it to lose an electron
• Trend in ionisation energy down group 2

  • Decreases
  • Greater atomic radius as well as increased shielding but similar nuclear charge
• Trend in boiling/melting points down group 2

  • Decreases
• Give the equation and observations for the reaction of Mg with water

  • Mg + 2H2O -> Mg(OH)2 + H2
  • Slow reaction
  • Alkaline solution
• Give the equation and observations for the reaction of Mg with steam

  • Mg + H2O (g) -> MgO + H2
  • Forms a white ppt
  • Fast reaction
• Solubility of the group 2 hydroxides and uses for them ( most -> least)

  • Ba(OH)2
  • Sr(OH)2
  • Ca(OH)2 - Controll the pH of soil
  • Mg(OH)2 - indigestion tablets
• Solubility of group 2 sulfates and there uses (most -> least)

  1. MgSO4
  2. CaSO4
  3. SrSO4
  4. BaSO4 - barium meals
• Why can BaSo4 be used as a medical tracer / barium meals

  • Insoluble
  • So isn't absorbed into the blood stream (good as it's toxic if it was absorbed)
• Equation for Mg in the extraction of titanium

  • TiCl4 + 2Mg -> 2MgCl2 + Ti
  • Extracts the Ti via a displacement reaction
• Equation for the removal of flue gas and what does it do?

  • CaO + 2H2O + SO2 -> CaSO3 + 2H2O
  • Removes pollutants