2.2 - Group 2 Metals Flashcards
Write the first ionisation energy of magnesium.
Mg (g) -> Mg^+ (g) +e^-
What happens to the first IE as you go down group 2? Why?
It decreases:
- increase in shielding
- increase in atomic radius
- means that there are weaker forces between the outer electron and the nucleus
- so less energy is required to remove the electrons
How does reactivity with water change as you go down group 2?
Increases (Mg least -> Ba most) because outer electrons are further away from the nucleus and there is more electron shielding, so electrons are lost more easily.
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 the group
- MgSO4 is soluble
- BaSO4 is insoluble
What is the trend in MP down group 2?
Decreases down the group beacuse the sea of delocalised electrons are futher away from the positive nucleus so there are weaker metallic bonds/ forces of attraction which takes less energy to weaken.
What is the trend in atomic radius down group 2?
- It increases as there more occupied electron shells down the group.
- It increases down the group due to a greater atomic number.
What are flue gases?
Gases produced by power stations which are harmful to the environment.
What is Mg(OH)2 used for?
Milk of magnesia - antacid to treat indigestion, heartburn, wind etc.
What is the use of BaSO4? Why is it safe?
In barium meals to outline gut in X-rays Ba2+ is toxic but is fine as barium sulphate is insoluble.
Write an equation for the reaction of Barium and water.
Ba(s) + 2H20 (l) —>Ba(OH)2 (s) + H2 (g)
Write an equation for the reaction of magnesium and steam.
Mg (s) + H2O (g) —> MgO (s) + H2 (g)
