Group 2 Alkaline Earth Metals

• Aldehydes have the general formula RCHO
• Ketones have the general formula RCOR'
• Alcohols have the general formula R-OH
• what ions do they form?

  2+
• what do alkaline earth metals react with?

  water
• what does magnesium react with?

  steam
• give the equation for group 2 metal reacting with water

  M + H2O -> M(OH)2 + H2
• give the equation for magnesium reacting with steam

  Mg + H2O -> MgO + H2
• how does reactivity change as you go down group 2?

  it increases
• Why does reactivity increase down group 2?

  First and second ionisation energies are smaller, atomic radius increases
• how does solubility with group 2 hydroxides change down the group?

  increases
• how does solubility with group 2 sulphates change down the group?

  decreases
• What is Mg(OH)2 used for?

  Milk of magnesia - antacid to treat indigestion, heartburn, wind etc.
• What is BaSO4 used for?

  It is used in medicine as a 'Barium meal' given to patients who need x-rays of their intestines. The barium absorbs the x-rays and so the gut shows up on the x-ray image
• if BaSO4 is toxic why is it used this way?

  insoluble so doesn't affect the body
• What is Ca(OH)2 used for?

  Neutralise acidic soil
• sulphate test

  Barium chloride then hydrochloric acid, white precipitate