Setting of plaster of Paris is
dehydration
oxidation with atmospheric oxygen
combination with atmospheric CO2
hydration to yield another hydrate
The set representing the right order of ionic radius is
Li+ > Na+> Mg2+ > Be2+
Mg2+ > Be2+> Li+> Na+
Na+> Mg2+> Li+> Be+
Na+> Li+> Mg2+> Be+
Atomic radius (pm) of Al, Si,N and F respectively is:
117, 143, 64, 74
143, 117, 74, 64
143, 47, 64, 74
64, 74, 117, 143
The correct order of hydration enthalpies of alkali metal ions is:
Li+ > Na+ > K+ > Cs+ > Rb+
Na+ > Li+ > K+ > Rb+ > Cs+
Na+ > Li+ > K+ > Cs+ > Rb+
Li+ > Na+ > K+ > Rb+ > Cs+
The covalent alkaline earth metal halide (X = Cl, Br, I) is :
MgX2
BeX2
CaX2
SrX2
B.
BeX2
Beryllium halides are covalent due to more polarizing power of small Be2+ ion with more charge density.
The isoelectronic set of ions is :
Li+, Na+, O2- and F-
N3-, O2-, F- and Na+
F-, Li+, Na+ and Mg2+
N3-,Li+, Mg2+ and O2-