C9 G2 Metals Flashcards
What are the Group 2 elements called?
Alkaline earth metals
What elements do they form?
+2 elements
What happens to the atomic radius as we go down the group?
It increases due to the addition of extra shells
What happens to 1st ionisation energy as we go down the group?
The ionisation energy decreases as we go down the group due to increased shielding so there is a weaker attraction between the nucleus and the outer electron so less energy is needed to remove the outer electron
What happens to the Melting points as we go down the group?
It decreases as we go down the group however magnesium is an exception due to its differing structure
What Structure do group 2 elements form?
They form metallic structure where the positive metal ions are attracted and surrounded by a sea of delocalised electrons
What happens to the size of the metal ion as we go down the group?
The size of the metal ion increases but the number of delocalised electrons remains the same
Why do larger ions have a weaker attractive force?
The distance between the + nuclei in metal ions and delocalised electrons is greater weakening the attractive forces
What do Group 2 metals form when they react with water?
They form bases which are known as metal hydroxides
Write the equation for the reaction of strontium with water
Sr(s)+2H2O(l) arrow Sr(OH)2(aq) + H2(g)
Why does magnesium react with steam instead of water?
Magnesium is an exception as it reacts slowly with cold water but more vigorously with steam producing magnesium oxide
What is the equation when magnesium reacts with steam?
Mg(s) + H2O(g) arrow MgO(s) + H2
Name the observations when magnesium reacts with steam
Magnesium burns to produce a bright white flame and produces a white powder
What is the general rule for negative ions with a double charge for group 2 compound solubility?
They become less soluble as you go down the group
What is the general rule for negative ions with a single charge for group 2 compound solubility?
They become more soluble as you go down the group
What compound neutralises acidic soils?
Ca(OH)2
What compound neutralises stomach acid and why?
Mg(OH)2 is used to neutralise stomach acid due to excess stomach acid being formed
What is a use of barium sulfate (BaSO4)?
It is used as medical tracers in X rays
How comes Barium sulfate is toxic but does not cause harm to the body?
This is due to the fact that barium sulfate is insoluble therefore the bodies bloodstream cannot absorb this
Describe the test for sulfates and the reagent used?
BaCl2 is used
1. Add HCl to remove any carbonates in. These could ppt out after adding BaCl2 giving a fake result
2. Add BaCl2
3. White ppt formed is any sulfates are present
What is the ionic equation for Barium sulfate?
Ba2+(aq) + SO42- (aq) arrow BaSO4 (s)
Describe the processes that occurs for the extraction of titanium?
1.Titanium dioxide is converted to titanium tetrachloride by heating carbon and chlorine gas
2.Titanium tetrachloride is passed through a fractional distillation column to increase purity
3. Purified Titanium tetrachloride is reduced using magnesium in a 1000* furnace
What is the equation for the extraction of titanium?
TiCl4 + 2Mg arrow Ti + 2MgCl2
Describe the process for the removal of sulfur dioxide?
Use either calcium oxide or calcium carbonate to remove the emissions via wet scrubbing. This is when an alkali is used to neutralise sulfur dioxide in the gases
What product is produced after the removal of sulfur dioxide?
Calcium sulfite
What is the equation for the removal of sulfur dioxide via calcium carbonate?
CacO3 (s) + 2H2O (l) + SO2 (g) arrow CaSO3 (s) + 2H2O (l) + CO2 (g)
What is the equation for the removal of sulfur dioxide via calcium oxide?
CaO (s) + 2H2O (l) + SO2 (g) arrow CaSO3 (s) + 2H2O (l)
Why does reactivity of water increase down the group?
Atoms get larger and electron is further from the nucleus so its easier to remove hence more reactive. More shielding
