Group 2

• What are Group 2 elements known as?

  Alkaline earth metals
• What happens to atomic radius as you go down Group 2?

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

  More electron shells are added
• What happens to 1st ionisation energy as you go down Group 2?

  Ionisation energy decreases down the group
• Why does ionisation energy decrease down Group 2?

  Atomic radius increases and shielding increases
• What is the general equation for Group 2 metals reacting with water?

  M(s) + 2H₂O(l) → M(OH)₂(aq) + H₂(g)
• How does magnesium react with cold water compared to steam?

  Very slow reaction with cold water
• What does magnesium produce when it reacts with steam?

  Magnesium oxide and hydrogen gas
• How does the solubility of Group 2 hydroxides change down the group?

  Solubility increases down the group
• What is an example of a Group 2 hydroxide's solubility?

  Mg(OH)₂ is sparingly soluble
• How does the solubility of Group 2 sulfates change down the group?

  Solubility decreases down the group
• What is an example of a Group 2 sulfate's solubility?

  BaSO₄ is insoluble
• How do you test for sulfate ions?

  Add acidified barium chloride solution
• What confirms the presence of sulfate ions?

  A white precipitate of BaSO₄
• What happens to Group 2 carbonates on heating?

  They decompose to form metal oxide and carbon dioxide
• How does thermal stability of Group 2 carbonates change down the group?

  Decomposition becomes more difficult down the group
• How is magnesium used in the extraction of titanium?

  It reacts with titanium(IV) chloride
• What is the equation for magnesium's reaction with titanium(IV) chloride?

  TiCl₄(g) + 2Mg(l) → Ti(s) + 2MgCl₂(l)
• What is calcium hydroxide used for in agriculture?

  To neutralise acidic soils
• Why is barium sulfate used in medical imaging?

  It absorbs X-rays and is insoluble
• How does calcium oxide remove sulfur dioxide from flue gases?

  It reacts to form calcium sulfite
• What is the equation for calcium oxide's reaction with sulfur dioxide?

  CaO + SO₂ → CaSO₃
• What are the flame test results for calcium?

  Brick red
• What are the flame test results for strontium?

  Red
• What are the flame test results for barium?

  Pale green
• What happens to the reactivity of Group 2 metals down the group?

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

  Ionisation energy decreases, electrons are lost easily
• What is the general equation for Group 2 metals reacting with acids?

  M(s) + 2HCl(aq) → MCl₂(aq) + H₂(g)
• What is the common oxidation state of Group 2 metals in their compounds?

  +2 due to losing 2 outer shell electrons
• How does the thermal stability of Group 2 nitrates change down the group?

  Thermal stability increases down the group
• Why does thermal stability increase down Group 2 nitrates?

  Larger cations have lower charge density
• What happens when Group 2 oxides react with water?

  They form alkaline hydroxides
• How does the pH of the solution change down the group when Group 2 oxides react with water?

  The pH increases as hydroxide solubility increases
• Why does the thermal stability of Group 2 carbonates and nitrates increase down the group?

  Larger cations cause less distortion of anions
• How does the thermal stability of Group 2 carbonates and nitrates relate to cation size?

  Larger cations have lower polarising power
• What type of ions do Group II metals form when they react?

  2+ ions
• Why does the atomic radius of Group II metals increase down the group?

  Due to additional electron shells
• Why does the reactivity of Group II metals increase down the group?

  Increased electron shielding makes outer electrons easier to lose
• Why does the first ionisation energy of Group II metals decrease down the group?

  Greater atomic radius and increased shielding
• Why do the melting points of Group II metals decrease down the group?

  Larger ions weaken attractive forces over greater distances