Group 2 Flashcards
What is group 2 also known as
Alkaline earth metals
What are the metals in group 2
Mg
Ca
Sr
Ba
What happens when magnesium reacts in water (steam)
Faster reaction
Extra energy
Magnesium oxide and hydrogen gas is produced
What happens when magnesium reacts in water(cold water)
Slower reaction
Magnesium hydroxide and hydrogen gas is produced
What is the solubility of group 2 metals in hydroxides
As you go down group 2 the more soluble it is
What is the least soluble group 2 hydroxide
Magnesium hydroxide which produces a white precipitate as it is insoluble
What is the most soluble group 2 hydroxide
Barium hydroxide as it is sparingly soluble
What is the solubility of group 2 in Sulfates
As you go down group 2 it becomes less soluble
What is the least soluble group 2 sulfates
Barium sulfate white precipitate as it is insoluble
What is the most soluble group 2 sulfate
Magnesium sulfate sparingly soluble
What is barium sulfate used for
Known as barium meal
Absorb x-rays as barium sulfate is insoluble so can be absorbed
What is magnesium hydroxide used for
Known as milk of magnesium /magnesia
Indigestion
Heartburn
What is calcium hydroxide used for
Neutralise acidic soil in agriculture
What is magnesium used for (extraction)
The extraction of titanium from titanium chloride
2Mg + TiCl4. ➡️ 2MgCl2 + Ti
Why is this extraction process costly
Equipment is expensive
Magnesium is expensive
High temperature used 1000 degrees
Batch process
Formula for hydroxides
Mg + 2H2O ➡️ Mg(OH)2 + H2
What is observed when magnesium is put in water
White flame
White powder
Formula for sulfates
Ba + H2SO4 ➡️ BaSO4 ➕H2
Ionic equation for barium sulfate
Ba2+ ➕. SO4(2-). ➡️BaSO4
Why is barium chloride acidified (test for sulfates)
The acid (HCL) reacts the carbonate impurities completely so a false positive result doesn’t happen
Why is sulphuric acid not used to test for sulfate ions (test for sulfate ions)
As sulphuric acid already contains sulfate ions so it would be a false positive result
What is observed when barium chloride reacts to form barium sulfate (test for sulfate ions)
White precipitate when sulfate ions are present
Use of calcium carbonate / calcium oxide
To remove flue gas from sulphur oxide
What happens are you go down group 2 in terms of atomic radius
Increases
Number of shells increase ,more shielding
What happens as you go down group 2 in terms of reactivity
Increases
Increase in shielding ,easier to lose electrons from the outermost shell
What happens as you go down group 2 in terms of melting point and boiling point
Decreases
Larger the ion,weaker force of electrostatic attraction between the nucleus and outer shell electrons
Greater distance to act on
What happens as you go down group 2 in terms of ionisation energy
Decreases
Increase in number of shells,more shielding
Decrease in nuclear charge
Weaker force of attraction between the positive nucleus and outer shell electron
Ionic equation for magnesium hydroxide
Mg(2+) ➕ 2OH(-). ➡️ Mg(OH)2
