group 2

• What happens to the number of delocalized electrons in group 2 elements as you move down the group?

  It stays the same
• How does the atomic radius and shielding change down group 2 elements?

  They increase down the group
• What happens to the attraction between delocalized electrons and metal cations as you move down group 2?

  It decreases
• Why is the melting point of magnesium considered anomalously low?

  It has a different crystal structure
• How does the reactivity of group 2 elements with water change down the group?

  It increases with greater atomic radius
• How does magnesium react with water?

  Very slowly with water, quickly with steam
• How does calcium react with cold water?

  It reacts with cold water
• How does barium react with cold water?

  It reacts vigorously with cold water
• How do group 2 elements react with hydrochloric acid?

  All react vigorously with HCl
• What happens when calcium reacts with sulfuric acid?

  It reacts vigorously at first, then slowly
• Why does calcium sulfate act as a protective layer during its reaction with sulfuric acid?

  It is insoluble and prevents further collisions
• What trend is observed in ionization energy down group 2 elements?

  It reduces down the group
• Why can't titanium be extracted directly?

  TiC is formed instead of Ti
• What are the properties of titanium that make it useful?

  Low density and corrosion resistant
• What is the main ore of titanium?

  Rutile, TiO2
• How is rutile converted to TiCl4?

  By adding chlorine and carbon gas
• What is the reaction that converts rutile to TiCl4?

  TiO2 + 2Cl2 + 2C → TiCl4 + 2CO
• How is TiCl4 purified?

  By fractional distillation in an Ar atmosphere
• What is the reaction to extract titanium from TiCl4?

  TiCl4 + 2Mg → Ti + 2MgCl2
• Why is the extraction process of titanium considered expensive?

  Due to heat, Mg, Ar, and batch process
• How does the solubility of hydroxides change down group 2?

  It increases down the group
• How does the solubility of sulfates change down group 2?

  It decreases down the group
• What is barium meal used for?

  • Used in X-ray studies
  • BaSO4 is insoluble
  • Won't be absorbed into bloodstream
  • X-rays won’t pass through barium meal
• What is milk of magnesia used for?

  • Mg(OH)2 used as an antacid
  • Found in toothpaste and indigestion tablets
  • Reaction: Mg(OH)2 + 2H+ → Mg2+ + 2H2O
• What is quick lime used for?

  • Ca(OH)2 used in agriculture
  • Neutralizes acid soils
  • Reaction: Ca(OH)2 + 2H+ → Ca2+ + 2H2O
• What is the purpose of desulfurization in flue gases?

  • CaO or CaCO3 used to remove SO2
  • Waste gases pass through scrubber
  • Reacts with CaO or CaCO3