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

$A$ mixture of sodium oxide and calcium oxide is dissolved in water and saturated with excess carbon dioxide gas. The resulting solution is ...... It contains ......... :

For a good quality cement,the ratio of lime to the total of the oxides of $Si$,$Al$ and $Fe$ should be as close as to :

Give the correct order of initials $T$ or $F$ for following statements. Use $T$ if statement is true and $F$ if it is false.
$(I)$ Number of $S-S$ bonds in $H_{2}S_{n}O_{6}$ is $(n - 1)$.
$(II)$ When $F_{2}$ reacts with water,it gives $HF, O_{2}$ and $O_{3}$.
$(III)$ $LiNO_{3}$ and $BaCl_{2}$ compounds are used in fireworks.
$(IV)$ $Be$ and $Mg$ hydrides are ionic and polymeric.

Match the average fundamental compounds with their proper percentage present in Portland cement.

Compound	Percentage proportion
$1. CaO$	$d. 50-60\%$
$2. Al_2O_3$	$a. 5-10\%$
$3. SO_3$	$b. 1-3\%$

On heating $ZnCl_2 \cdot 2H_2O$,the compound obtained is