Group 2 - Chemistry

• A common name given to group 2 elements is alkaline earth metals
• The most reactive metal of group 2 is Barium
• 3 physical properties of group 2 metals:

  • High melting point and high boiling points
  • low density metals
  • form colourless compounds
• The highest energy electrons are in the s orbital, the lowest energy electrons are in the p orbital
• Reactivity increases down group 2 as electrons are lost more easily as there is an increase of atomic radius and increase of shielding
• What happens to the first ionisation energy as you go down group 2? Why?

  Decreases because:

  -Number of filled electron shells increases down the group → increased shielding

  • Increased atomic radius → weaker force between outer electron and nucleus → less energy needed to remove electron
• What type of reaction is the reaction between group 2 elements and oxygen?

  Redox reaction
• Write an equation for the reaction of calcium and oxygen

  2Ca (s) + O2 (g) → 2CaO (s)
• What is the product when group 2 elements react with water?

  Hydroxide and hydrogen gas
• Which group 2 element doesn’t react with water?

  Beryllium
• Which group 2 element reacts very slowly with water?

  Magnesium
• Write an equation for the reaction of Barium and water

  Ba (s) + 2H2O (l) → Ba(OH)2 (aq) + H2 (g)
• What is oxidised and what is reduced in a reaction between group 2 metal and water?

  Metal → oxidised

  One hydrogen atom from each water → reduced
• What is the drawback of using calcium carbonate in construction? Write a related equation

  Group 2 carbonates react with acid

  CaCO3 (s) + 2HCl(aq) → CaCl2 (aq) + H2O (l) + CO2(g)
• What is calcium carbonate used for?

  Present in limestone and marble Used in building construction
• What is Mg(OH)2 used for?

  Milk of magnesia - antacid to treat indigestion, heartburn, etc.
• What is Ca(OH)2 used for? Write an equation related to one of its uses

  Used to neutralise soil

  Ca(OH)2 (aq) +2HCl (aq) → 2H2O (l) + CaCl2 (aq)
• What is the trend in hydroxide solubility down group 2?

  Increases down the group

  Mg(OH)2 is slightly soluble

  Ba(OH)2 creates a strong alkaline solution
• What are the products when group 2 element reacts with dilute acid?

  Salt and hydrogen gas
• Write an equation for the reaction of calcium and hydrochloric acid

  Ca (s) + 2HCl (aq) → CaCl2(s) + H2 (g)
• What is formed when group 2 oxides react with water?

  Metal hydroxide
• Write an equation for the reaction between a group 2 oxide and water

  MO (s) + H2O (l) → M(OH)2 (aq)
• Which group 2 metal oxide is insoluble in water?

  Beryllium oxide
• What is the trend in hydroxide solubility down group 2?

  Increases down the group

  Mg(OH)2 is slightly soluble

  Ba(OH)2 creates a strong alkaline solution