Group 2

• Group to reactions with water

  M = any group 2 element

  M + 2 H20 == M(OH)2 + H2

  
  

  Reaction of Mg with steam =

  Mg + H20(g) == MgO +H2

  
  

  Burns to form a white powder
• Group 2 ionic equations:

  M = any group 2 element

  M == M2+ + 2e-
• As we go down the group reactivity increases:

  As the Atoms get bigger therefore weaker attraction to the nucleus + More shielding so easier to oxidise
• Solubility of hydroxides:

  Increases as we go down the group so Mg(OH)2 is the least insoluble,

  Be does not react
• Solubility of the sulphates:

  Decreases as we go down the group,

  BaSO4 is the least soluble
• Mg(OH)2 can be used as: antacids, indigestion tables
• BaSO4 Can be used in Barium meal and in X rays

  Insoluble therefore does not harm the body
• Ca(OH)2 can be used in neutralising soil
• Sulphates test:

  Add HCl to remove any unwanted ions

  Add BaCl2

  Positive result = White precipitate of BaSO4

  Equation:

  BaCl2 +H2SO4 == BaSO4 + 2HCl