Group II - The Alkaline Earth Metals Quiz

Study Notes

Group II - The Alkaline Earth Metals

Group II metals lose two electrons to form 2+ ions when they react.
Atomic radius increases down the group due to the addition of electron shells.
Reactivity increases down the group as the increased electron shielding makes the outer electrons easier to lose.
Ionisation energy decreases down the group due to greater atomic radius and increased shielding.
Melting points decrease down the group as the larger the ions within the metallic structure, the weaker the attractive forces.
Group II metals react with water in a redox reaction to produce a metal hydroxide and hydrogen.
The metal hydroxide form an alkaline solution, hence why the group II metals are known as the alkali metals.
Magnesium reacts very slowly with liquid water but the reaction can be much faster with steam, as it provides extra energy.
When steam is used, the magnesium burns with a bright white flame to form hydrogen and magnesium oxide, a white powder.
Solubility of group II hydroxides increases down the group. Magnesium hydroxide is the least soluble and barium hydroxide is the most soluble.
Magnesium hydroxide is used in medicine as an antacid due to its alkaline nature.
Magnesium hydroxide is also used in agriculture to neutralise acidic soils.
Solubility of group II sulfates decreases down the group. Magnesium sulfate is the most soluble and barium sulfate is the least soluble.
The insolubility of barium sulfate makes it useful in medicine as barium meals, a form of medical tracer.
Barium sulfate is safe to use as it cannot be absorbed into the bloodstream.
Barium chloride is used as a test for sulfate ions as it reacts to form barium sulfate, a white precipitate when sulfate ions are present.
Magnesium is used in the extraction of titanium from titanium chloride via a displacement reaction.
Calcium oxide reacts with sulfur dioxide in flue gas removal to prevent its release into the atmosphere.
This reaction forms calcium sulfite and water.