Group 2

• What structure do alkaline earth metals form?

  They form giant metallic lattices
• What trend occurs in atomic radius as you move down group 2?

  Atomic radius increases down the group
• Why does atomic radius increase down group 2?

  More electron shells are added
• What trend occurs in first ionisation energy as you move down group 2?

  First ionisation energy decreases down the group
• Why does first ionisation energy decrease down group 2?

  Outer electrons are further from the nucleus
• What happens to the melting and boiling points of group 2 metals as you go down the group?

  They generally decrease down the group
• Why does the melting point of magnesium differ from other group 2 metals?

  Its crystal structure changes
• What trend occurs in reactivity as you move down group 2?

  Reactivity increases down the group
• Why does reactivity increase down group 2?

  It is easier to lose electrons
• What is the general reaction of alkaline earth metals with water?

  Metal + water → metal hydroxide + hydrogen
• What is the appearance of magnesium oxide produced from its reaction with steam?

  It is a white powder
• What do hydroxides form when a metal reacts with water?

  They form white solids
• How does solubility of hydroxides change down group 2?

  More soluble down the group
• What are the solubilities and uses of group 2 hydroxides?

  • Mg(OH)₂: Least soluble, used as an antacid
  • Ca(OH)₂: Sparingly soluble, used in agriculture
  • Sr(OH)₂: More soluble
  • Ba(OH)₂: Most soluble, produces strongly alkaline solutions
• What trend occurs in solubility of sulfates down group 2?

  Less soluble down the group
• What are the solubilities and uses of group 2 sulfates?

  • MgSO₄: Most soluble
  • CaSO₄: More soluble
  • SrSO₄: Sparingly soluble
  • BaSO₄: Insoluble, used in barium meals
• What is the purpose of using BaCl₂ in sulfate testing?

  It forms white insoluble barium sulfate precipitate
• Why must BaCl₂ testing be acidified?

  To remove carbonate ions that cause false positives
• What is the overall reaction when testing for sulfates with BaCl₂?

  Ba²⁺ + SO₄²⁻ → BaSO₄ (s)
• How is titanium extracted using magnesium?

  By reducing titanium chloride with magnesium
• What is the exception for magnesium's reactivity with water?

  Reacts slowly with cold water
• What is calcium hydroxide used for in agriculture?

  To neutralise acidic soils
• What is magnesium hydroxide used for?

  As an antacid to neutralise stomach acid
• Why is barium sulfate safe for medical use despite being toxic?

  It is insoluble and not absorbed
• How do group 2 compounds help reduce sulfur dioxide emissions?

  They neutralise acidic gases
• What products are formed when calcium carbonate reacts with sulfur dioxide?

  Calcium sulfate and carbon dioxide
• Write the equation for the reaction of magnesium with steam

  Mg$(s)$ + H2O$(g)$ $\rightarrow$ MgO$(s)$ + H2$(g)$
• Write the equation for the removal of titanium using magnesium

  TiCl4(l) + 2Mg(l) ➔ Ti(s) + 2MgCl2(l)