Group 2 Flashcards
When a group 2 metal react with water what is produced and what does the vigour depend on?
Metal hydroxide and hydrogen
Vigour -
-how easily two electrons are removed from the atom
-how. Soluble the hydroxides of metals are= reactivity increases down the group
What happens with solubility of Group 2 sulfates going down the group?
Decreases down the group
MgSO4-soluble
CaSO4-sparingly soluble
SrSO4 and Ba4-insoluble
Describe the precipitates you will see with Group 2 sulfates?
Mg =no ppt formed
Ca=faint white ppt
Ba , Sr=thick white ppt formed
Describe how to test for sulfate ions?
-1cm^3 of aq BaCl and 1cm^3 of dilute HCL\
-unknown solution with have a thick white ppt and it will not dissolve in dilute hcl
What is the role of HCl in test for sulfate ions?
Removes any other ions e.g Carbonates or OH
What are the solubilities of Group 2 hydroxides?
Increase down the group
-Mg(OH)2=insoluble
-Ca(OH)2=sparingly soluble
-Sr(OH)2 and Ba(OH)2=soluble
Describe the precipitates you will see with Group 2 hydroxides?
-Mg=white ppt
-Ca=faint white ppt
-Sr and Ba=no reactions
What is a use of Mg(OH)2?
Milk of magnesia= alleviate constipation
what is the use of Ca(OH)2?
Slaked lime to neutralise acidic soil
What is a use of BaSO4?
Barium meal , barium is good at absorbing X rays and is harmless as BaSO4 is insoluble
Describe how Titanium is extracted?
-Using two magnesium
2Mg + TiCl4 -> 2MgCl2 +Ti
What is a use of CaO and CaCO3?
Flue Gas Desulfurisation
What are the steps in Flue Gas Desulfurisation?
-CaO + SO2 + 2H2O -> CaSO3 + 2H2O
-CaCO3 + SO2 + 2H2O -> CaSO3 + 2H20 +CO2
What happens to the reactivity of Group 2 elements going down?
Reactivity increases as the electrons are lost more easily
What happens to the ionic radius of Group 2 elements going down?
It increases going down as there is a lower charge density so a weaker attraction
