Group 2 Flashcards
What happens when a group (II) metal reacts with water?
The metal atom loses electrons and becomes a 2+ metal ion
Elements become less reactive as you go down a group. True or false
False - becomes more reactive because the atoms become larger so the distance between the nucleus and outer e- is greater
What does a more vigorous reaction mean in terms of collisions?
More (successful) collisions in a given time
When Mg reacts with H2O what two different products could be made? What is the speed of their respective reactions
Mg(OH)2 - v slow
Or
MgO - fast
What are the 2 trends in solubility for group 2 hydroxides
1) Solubility increases down the group
2) the strength of the hydroxide as a base increases down the group because there are more hydroxide ions in the solution
When NaOH is added to MgCl2
What is produced?
When NaOH is added to BaCl2 what is produced?
A white precipitate of Mg(OH)2
No precipitate as Ba(OH)2 is soluble in water
What is the test for hydroxide ions
MgCl2 solution is added and a white precipitate of Mg(OH)2 is formed
What is he test for Mg2+ ions
NaOH is added and a white precipitate of Mg(OH)2 is formed
What is the trend in solubility of group 2 sulphates
Solubility decreases down the group
What is used to test for sulphate ions
Why
Acidified barium chloride
Barium sulphate is insoluble so a white precipitate is produced
What acids can and cannot be used to acidity a solution containing barium ions
Can: HCl or HNO3 to remove carbonate ions
Cannot: H2SO4 as it contains sulphate ions so a white precipitate of BaSO4 would form
How do you test for barium ions
Add sulphuric acid and a white precipitate of BaSO4 is formed
Test for sulphate ions
Add Acidified BaCl2
A white precipitate of BaSO4 is formed
Name a use of Mg(OH)2
Medicine to treat indigestion
To neutralise excess stomach acid
Name a use of Ca(OH)2
Used in agriculture to neutralise acidity in soils
Use of BaSO4
Why is it not dangerous despite being poisonous
Medicine in X Rays to examine oesophagus, stomach and intestine. It coats them in a material that cannot be absorbed so unhealthy areas can clearly be seen
It is insoluble so cant be absorbed by the body
How is titanium extracted
Reducing titanium chloride by a more reactive metallic
How is TiO2 converted to titanium(IV) chloride
What is the next step in the extraction
Using chlorine and coke at 900 degrees C
Titanium chloride is a liquid which fumes in moist air and is purifies by fractional distillation in argon
Equation for converting TiO2 into TiCl4
TiO2(s)+2Cl2(g)+2C(s)
—->
TiCl4(g) + 2CO(g)
How is Mg uses in the extraction of titanium
As a reducing agent
It is heated with the titanium Chloride in a crucible in argon at 600 degrees C
Why is an atmosphere of argon used to extract Titanium
To prevent oxidation
Equation for reduction of titanium chloride
TiCl4(g) + 2Mg(l) —>
Ti(s)+2MgCl2(l)
What is flue gas desulphurization
The removal of SO2 from the gases emitted by fossil fuel power plants and other SO2 emitting processes
What is used to remove SO2?
Why these compounds?
CaO or CaCO3
To neutralise the SO2 as it is an acidic gas
