Setting of plaster of Paris is
dehydration
oxidation with atmospheric oxygen
combination with atmospheric CO2
hydration to yield another hydrate
Which one of the following will not give flame test?
Ca
Ba
Sr
Be
D.
Be
Beryllium having smallest atomic size in the group 2 has tightly held outermost electrons that do not get excited significantly during flame test.
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-