Group 2 Flashcards
What happens to reactivity as you go down group 2 and why?
Increases - Increased size of atom, shielding effect increases as well as distance from nucleus, so easier to lose outermost electrons due to decreased attraction between nucleus and outer electrons
What happens to 1st ionisation energy as you go down group 2 and why?
Decreases - increased shielding effect, less attraction between nucleus and outer electron, easier to lose outer electrons
What happens to melting point as you go down the group?
Decreases - weaker metallic bonding as metal ions get larger, less attraction between nucleus and delocalised electrons
What is produced when a group 2 metal reacts with water?
metal hydroxide and hydrogen gas
x + 2H₂O → x(OH)₂ + H₂
(Be has no reaction)
What is produced when Mg reacts with steam?
Mg + H₂O → MgO + H₂
As you go down the group, what happens to the solubility of the hydroxides?
Increases, Mg(OH)₂ is least soluble
As you go down the group, what happens to the solubility of the sulfates?
Decreases (Mg to Ba)
What is the SO₄²- test?
Add HCl and BaCl₂, which will react to form BaSO₄, which is insoluble and forms a white precipitate.
What is Mg(OH)₂ used for?
Antacids (indigestion tablets)
What is BaSO₄ used for?
Barium meal - eaten before x rays as it absorbs x rays
Why is BaSO₄ not toxic?
Because BaSO₄ is insoluble
What is Ca(OH)₂ used for?
Used to neutralise acidic soil
What is used in flue gas removal (SO₂) ?
CaO, CaO3
CaO + H₂O + SO₂ forms…
CaSO3 + 2H₂O
CaCO3 + 2H₂O + SO₂ forms…
CaSO3 + 2H₂O + CO₂
