$MgO$ is used for lining furnaces because

In the hardening stage of Plaster of Paris, the compound formed is:

Addition of an oxalate solution to an aqueous solution containing a mixture of $Ba^{2+}$,$Sr^{2+}$,and $Ca^{2+}$ ions will precipitate:

Why are the elements of group-$2$ known as alkaline earth metals?

$Mg(NO_3)_2 \cdot XH_2O$ and $Ba(NO_3)_2 \cdot YH_2O$ represent the formulas of the crystalline forms of nitrate salts. The sum of $X$ and $Y$ is $.........$.

Which halide of alkaline earth metals is covalent in nature and can be soluble in organic solvent, such as ethanol?