3.2.2 Group 2, the alkaline earth metals Flashcards
write an equation for the first ionisation energy of magnesium
Mg (g) —> Mg + (g) + e-
what happens to first ionisation energy as we go down group 2? why?
decreases
increased shielding
increased atomic radius
weaker attraction between nucleus and outer electrons
less energy needed to remove outer electron
how does reactivity with water change as we go down group 2? why?
increases
outer electrons further from nucleus
more shielding
outer electrons lost more easily
write the equation for the reaction of barium and water.
Ba (s) + 2H2O (l) —> Ba(OH)2 (aq) + H2 (g)
write an equation for the reaction between magnesium and steam,
Mg (s) + H2O (g) —> MgO (s) + H2 (g)
what is the trend in solubility down group 2?
increases
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
MgSO4 is soluble
BaSO4 is insoluble
what is the trend in melting point going down group 2? why?
decreases
sea of delocalised electrons is further from the nucleus
weaker metallic bonds / forces of attraction
take less energy to weaken
what is the trend in atomic radius going down group 2? why?
increases
more occupied electron shells down the group
what are flue gases?
gases produced by power stations which a
what can we use to remove flue gases?
CaCo2
CaO
name an example of a flue gas.
SO2 (sulfur dioxide)
what is Ca(OH)2 used for?
neutralise soil
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 this safe?
in barium meals to outline gut in X-rays
Ba2+ is toxic but is fine as barium sulphate is insoluble
