3.1.2 Group 2 Flashcards
What is a common name given to group 2 metals?
- Alkaline earth metals
What is the most reactive metal of group 2?
- Barium
List 3 physical properties of group 2 metals.
- High melting and boiling points
- Low density metals
- Form colourless (white) compounds
The highest energy electrons of group 2 metals are in which subshell?
- S subshell
Does reactivity increase or decrease down group 2? Why?
- Increases
- Electrons are lost more easily because of larger atomic radius and more 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 are the products 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
What type of reaction is the reaction between group 2 metals and water?
- Redox reaction
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 metals and water?
- Metal -> oxidised
- One hydrogen atom from each water -> reduced
What are the products when a group 2 element reacts with a dilute acid?
- Salt and hydrogen gas
Write an equation for the reaction of calcium and hydrochloric acid.
- Ca (s) + 2HCl (aq) -> CaCl₂ (aq) + 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
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 Mg(OH)₂ used for?
- Milk of magnesia - antacid to treat indigestion, heartburn, etc.
What is calcium carbonate used for?
- Present in limestone and marble
- Used in building construction
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)
