Which of the following alkaline earth metals forms complex salts?

Which of the following sulphates is insoluble in water?

Among the alkaline earth metals $(Group \, 2)$ $Be, Mg, Ca,$ and $Sr$,which one forms the least ionic chloride?

In which of the following exothermic reactions,the heat liberated per mole is the highest?

Match List-$I$ with List-$II$ for the compositions of substances and select the correct answer using the codes given below.

List-$I$ (Substances)	List-$II$ (Composition)
$A$. Plaster of Paris	$i$. $CaSO_4 \cdot \frac{1}{2} H_2O$
$B$. Epsomite	$ii$. $MgSO_4 \cdot 7H_2O$
$C$. Kieserite	$iii$. $MgSO_4 \cdot H_2O$
$D$. Gypsum	$iv$. $CaSO_4 \cdot 2H_2O$
	$v$. $CaSO_4$

Identify the correct statements from the following:
$I$. All alkaline earth metals give hydrides on heating with hydrogen.
$II$. Calcium hydroxide is used to purify sugar.
$III$. $BeCl_2$ is a dimer in gaseous phase.