7 Group 2 & 7 Flashcards
Trend in Atomic radium down G2
Increases
More shells
More Dist Less Attract
More shielding
Trend in First IE Grp2
Decreases
More shielding
More shells
More distance
Less attract
Easier to remove e
Trend in water reactivity g2
Increases
more reducing power
easier to donate e due to increased Ar
Equation of G2 metal and water
Mg + 2H2O –> Mg(OH)2 + H2
Equation of G2 metal and steam
Explain why products form
Mg + H2O (g) –> MgO + H2
not stable to produce hydroxide, thermal decomposition
Trend in MP G2
Decreases
Ar inceases
Less attraction between positive metal ions and delocalised e.
Strength of metallic bonds decrease
Trend in solubility of G2 OH
Mg sparingly Ba soluble
Explain why Mg OH2 is sparingly soluble and not just insoluble
Slightly alkaline solution indicating some OH ions are dissolved in water
Reactions between G2 and water observations
Amount of precipitate formed decreases down grp, all white ppt, fizzing in all.
Test for Mg2+ in MgCl2
Add NaOH solution.
White ppt forms.
Explain a use of magnesium.
Extract titanium from titanium chloride:
TiO2 + 2Cl2 + C → TiCl4 + CO2
TiCl4 (l) + 2Mg (s) → 2MgCl2 (s) + Ti (s)
Very difficult to extract titanium from its ores (TiO2).
Initially converted to the chloride, then reduced by magnesium.
Use of Mg OH
Constipation and Antacid as its slightly alkaline and doesn’t irritate oesophagus.
Use of Ca OH
Neutralise acidic soil
Ca(OH)2 (aq) +2HCl (aq) → 2H2O (l) + CaCl2 (aq)
Use of calcium Oxide/ Carbonate
Flue gas removal
CaCO3 (s) + SO2 (g) → CaSO3 (s) + CO2 (g)
CaO (s) + SO2 (g) → CaSO3 (s)
Use of barium sulphate?
barium meals, outline gut in x rays, insoluble so safe.