S block Flashcards
Name the Group 2 elements
Be, Mg, Ca, Sr, Ba, Ra
Why are group 2 elements called Alkaline Earth metals
Alkaline - they form basic oxides or hydroxides
Earth - found in crust and high thermal stability
Why is Be not Alkaline earth metal
It forms amphoteric oxide instead of basic ( BeO )
Abundance order of Group 2 metals
Ca (5th) > Mg (6th) > Ba > Sr > Ra
Relation between Hydration enthalpy, Lattice enthalpy and size
Hyd and Latt inverse to size ( lattice enthalpy is affected more by changes )
Which 2A ion is largest in aqueous solution
Be2+ is largest due to high hydration enthalpy
What are flame test colours of 2A elements
Ca - brick red Sr - crimson Ba - apple green
Be & Mg - No colour ( tightly bound electrons )
Reaction of 2A metals with Air and water
Be & Mg ( solid ) - no reaction ( oxide film )
Ca, Sr , Ba ( solid ) Be Mg ( powder ) - XO and X3N2
Be and Mg ( powder ) with only hot water
Ca, Sr ,Ba ( solid ) with cold water ( vigorous )
Relation between Hydration energy, reducing power, Electrode potential
Hydration energy prop Reducing power prop 1/electrode potential
2 uses of Beryllium
hint : Cu - Be, Metallic Be
Cu - Be alloy = high strength springs
Metallic Be = X ray tube windows
Uses of Ca Ba Ra
Ca - Extraction of metals
Ca & Ba - removing air from vacuum tubes
Ra - Radiotherapy
4 uses of Mg
hint: Mg - Al ,MgOH ,MgCO3 ,Mg powder
Mg - Al = Aircraft construction
MgOH = milk of magnesia
MgCO3 = toothpaste
Mg powder = flash powders, bulbs, bombs, signals
Which compounds of S - block are relatively more covalent
Li , Be , Mg due to high ionization enthalpies
