Group 2 Flashcards
What is the trend in solubility of group II hydroxides?
Solubility increases down the group
Magnesium hydroxide (Mg(OH)2) is the least soluble and barium hydroxide (Ba(OH)2) is the most soluble.
What is magnesium hydroxide used for?
Used in medicine as an antacid and in agriculture to neutralise acidic soils
It is alkaline and can neutralise acids.
What is the trend in solubility of group II sulfates?
Solubility decreases down the group
Magnesium sulfate (MgSO4) is the most soluble and barium sulfate (BaSO4) is the least soluble.
Why is barium sulfate useful in medicine?
It is insoluble and can be used as a medical tracer
Barium meals allow internal tissues and organs to be imaged safely.
What reaction occurs when barium chloride is used as a test for sulfate ions?
Barium sulfate forms as a white precipitate
The reaction is Ba^2+ + SO4^2- → BaSO4(s).
What is the role of magnesium in the extraction of titanium?
Magnesium is used to displace titanium from titanium chloride
The reaction is TiCl4 + 2Mg → 2MgCl2 + Ti.
What does calcium oxide react with to remove pollutants?
Calcium oxide reacts with sulfur dioxide
This forms calcium sulfite and water.
What is the reaction for flue gas removal using calcium oxide?
CaO + 2H2O + SO2 → CaSO3 + 2H2O
This process prevents sulfur dioxide from being released into the atmosphere.
What charge do Group II metals form when they lose electrons?
Group II metals lose two electrons to form 2+ ions.
How does the atomic radius of Group II metals change down the group?
The atomic radius increases down the group due to additional electron shells.
What effect does increased electron shielding have on the reactivity of Group II metals?
Increased electron shielding makes the outer electrons easier to lose, increasing reactivity down the group - weaker FOA
How does the first ionisation energy of Group II metals change down the group?
The first ionisation energy decreases down the group due to a greater atomic radius and increased shielding so weaker force of attraction between nucleus and outer electron.
What is the trend in melting points of Group II metals down the group?
Melting points decrease down the group as larger ions weaken the attractive forces in the metallic structure.
What do Group II metals produce when they react with water?
They produce a metal hydroxide and hydrogen in a redox reaction.
What is the general reaction of magnesium with water?
Mg + 2H₂O → Mg(OH)₂ + H₂
Magnesium is oxidised from oxidation state 0 to +2.
How does magnesium react with steam compared to liquid water?
Magnesium reacts very slowly with liquid water but much faster with steam, burning with a bright white flame to form hydrogen and magnesium oxide.
What is the reaction of magnesium with steam?
Mg + H₂O → MgO + H₂
