Setting of plaster of Paris is
dehydration
oxidation with atmospheric oxygen
combination with atmospheric CO2
hydration to yield another hydrate
Which alkaline earth metal compound is volatile?
Mg3N2
Ca3N2
Be3N2
None of the equation
C.
Be3N2
Be3N2 is volatile due to greater tendency of covalent character in Be and N atoms. All other nitirdes are of ionic nature.
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 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-