Group 2 metals Flashcards
Write an equation for the first ionisation energy of magnesium
Mg (g) → Mg+ (g) + e
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
How does reactivity with water change as you go down group 2?
Increases
Because outer electrons further from nucleus and more
electron shielding, so electrons are lost more easily
Write an equation for the reaction of Barium and water
Ba (s) + 2H2O (l) → Ba(OH)₂ (aq) + H₂ (g)
Write an equation for the reaction of Magnesium and steam.
Mg (s) + H₂O (g) → MgO (s) + H₂ (g)
What is the trend in
hydroxide solubility down group 2?
Increases down the group Mg(OH)₂ is almost insoluble
Ba(OH)₂ creates a strong alkaline solution
What is the trend in
sulphate solubility down group 2?
Decreases down group MgSO₄ is soluble BaSO₄ is insoluble
What is the trend in melting point down group 2? Why?
Decreases down group
Because sea of delocalised electrons is further from the positive charge of the nucleus → weaker metallic bonds / forces of attraction which take less energy to weaken
What is the trend in atomic radius down group 2?
Increases as there are more occupied electron shells down the group
Write the equations for the extraction of Titanium using Magnesium
TiO₂ + 2Cl₂ + C →TiCl₄ + CO₂
TiCl₄ (l) + 2Mg (s) → 2MgCl₂ (s) + Ti (s)
What are flue gases?
Gases produced by power stations which are harmful to the environment
How can CaO or CaCO3 be used to remove flue gases?
Write equations
CaCO₃ (s) + SO₂ (g) → CaSO₃ (s) + CO₂ (g)
CaO (s) + SO₂ (g) → CaSO₃ (s)
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, wind etc.
What is a use of BaSO4? Why is this safe?
In barium meals to outline gut in X-rays
Ba²+ is toxic but is fine as barium sulphate is
insoluble
