Inorganic: Group 2 Flashcards
Explain the trend in atomic radius down group 2
Increases as you go down the group
Because the number of electron shells increase as you go down the group
Explain the trend in first ionisation energy as you go down group 2
Decreases as you go down the group
Because the number of electron shells increases
So there is more shielding and the outermost electron is more weakly attracted to the positive nucleus
So requires less energy to remove
Why does it not matter that the number of protons also increases as you go down the group
Increase in shielding counteracts this
explain the trend in melting points of the group 2 elements
group 2 elements form metallic structures containing positive ions in a sea of delocalised electrons
As you go down the group the size of the metal ion increases but the charge and number of delocalised electrons remains the same
Larger ions means the distance between the positive nucleus and the delocalised electrons is greater. This means the attraction between the +ve ions and the delocalised electrons is weaker so the electrostatic forces of attraction require less energy to overcome
Therefore melting points decrease as you go down group 2
Give a general equation for the reaction of G2 metals with water
M+2H2O>M(OH)2 + H2
What is produced when g2 metals react with water
Base and hydrogen gas
What is the trend for reactivity of g2 metals with water and explain this trend
Increase in reactivity as you go down the group
aTOMS GET LARGER SO OUTERMOST ELECTRONS ARE FURTHER FROM THE NUCLEUS SO MORE WEAKLY ATTRACTED. THIS MEANS THEY ARE EASIER TO REMOVE SO ARE MORE REACTIVE
Given the trend in reactivity, which g2 metal does not react with water
Berylium
Compare Mg reacitons with H2O based on its temperature
Mg reacts slowly with cold water and more vigorously with steam
When Mg reacts with steam it produces MgO instead of Mg(OH)2
What is the trend in solubulities of the group 2 hydroxides
Solubility increases as you go down the group
What is the trend in solubulities of the group 2 sulphates
Decreases as you go down the group
How do you test for sulfates
Add HCl to remove any carbonates that could give a false positive
Add Barium Chloride
barium SULFATE white ppt will form as BaSO4 is insoluble
Describe the use of Calcium Hydroxide in agriculture
Used to neutralise acidic soils
Describe the use of Magnesium Hydroxide in Medicine
Used to neutralise excess stomach acid
How is calcium oxide or calcium carbonate good for combatting pollution
Used to remove sulfur dioxide from flue gases
What is wet scrubbing
When CaO OR CaCO3 is sprayed onto acidic sulfur dioxide gas
What are the products of wet scrubbing
Calcium sulfite, Water (+co2 sometimes)
Explaun the use of Barium Sulfate in medcine
Barium Sulfate is dense
Barium sulfate is used in meals for people to receive GI scans and so problems in the soft tissue that would not normally show up on x-ray show up
Why can people eat barium sulfate containing compounds given that barium containing compounds they are toxic
BaSO4 is insoluble so not absorbed into the bloodstream
Describe how Magnesium is used to extract titanium from its ore
TiO2 converted into TiCl4 by heating with C and Cl2 gas
TiCl4 passed through fractional distillation column to increase purity
TiCl4 reduced with magnesium in 1000c furnace
State the equation for the reduction of TiCl4 by Mg
TiCl4 + 2Mg > Ti + 2MgCl2
