Green vitriol is . . . .

Consider three metal chlorides $x$, $y$ and $z$, where $x$ is water soluble at room temperature, $y$ is sparingly soluble in water at room temperature and $z$ is soluble in hot water. $x$, $y$ and $z$ are respectively:

Which of the following orders is correct?

$A$ pink colored salt on dry heating becomes blue in colour. The salt may contain:

The initial setting of cement is primarily due to which of the following?

Match List-$I$ with List-$II$:

List-$I$	List-$II$
$A$. $Na_2CO_3 \cdot 10H_2O$	$I$. $Caustic \ soda$
$B$. $NaOH$	$II$. $Slaked \ lime$
$C$. $Ca(OH)_2$	$III$. $Baking \ soda$
$D$. $NaHCO_3$	$IV$. $Washing \ soda$