In the following reactions the sum of the total number of atoms in one molecule of (A),(B) & (C) is

$$\begin{gathered} \mathrm{NaCl}+{\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7+{\mathrm{H}}_2{\mathrm{SO}}_4\to \left(\mathrm{A}\right)+\mathrm{side}\mathrm{products} \\ \left(\mathrm{A}\right)+\mathrm{NaOH}\to \left(\mathrm{B}\right)+\mathrm{side}\mathrm{products} \\ \left(\mathrm{B}\right)+{\mathrm{H}}_2{\mathrm{SO}}_4(\mathrm{dil}.)+{\mathrm{H}}_2{\mathrm{O}}_2\to \left(\mathrm{C}\right)+\mathrm{side}\mathrm{products} \end{gathered}$$

Balance the given chemical equation in a stepwise manner:

$\mathrm{HCl}+\mathrm{Zn}\underset{}{\to }$${\mathrm{ZnCl}}_2+{\mathrm{H}}_2$

27. A non-metallic element is converted into a compound X after a series of reactions. A little amount of X when tested with blue litmus turns to red. X on complete reaction with another compound Y gave the product which did not respond to litmus test. Identify the correct sequence of the reactions.

(1) $2{\mathrm{SO}}_2+{\mathrm{O}}_2\to 2{\mathrm{SO}}_3$

(2) ${\mathrm{H}}_2{\mathrm{SO}}_4+2\mathrm{KOH}\to {\mathrm{K}}_2{\mathrm{SO}}_4+2{\mathrm{H}}_2\mathrm{O}$

$\left(3\right){\mathrm{SO}}_3+{\mathrm{H}}_2\mathrm{O}\to {\mathrm{H}}_2{\mathrm{SO}}_4$

$\left(4\right)\mathrm{S}+{\mathrm{O}}_2\to {\mathrm{SO}}_2$

Complete and balance the following equations

(ⅰ ) ${\mathrm{N}}_2$ +${\mathrm{H}}_2$$\to$ $.....$

(ⅱ) ${\mathrm{NH}}_3$ +$$\begin{gathered} {\mathrm{Cl}}_2 \\ Excess \end{gathered}$$ $\to$$.....$

(ⅱⅰ) $\mathrm{PbO}$ + ${\mathrm{NH}}_3$ $\to$$.....+....+{\mathrm{H}}_2\mathrm{O}$

(ⅳ) ${\mathrm{NH}}_3$ + ${\mathrm{O}}_2$ $$\begin{gathered} \stackrel{\mathrm{pt}}{\to } \\ 800°\mathrm{C} \end{gathered}$$$.....+......$

In the given reactions,

$1){\mathrm{I}}_2+{\mathrm{H}}_2{\mathrm{O}}_2+2{\mathrm{OH}}^{–}\to 2{\mathrm{I}}^{–}+2{\mathrm{H}}_2\mathrm{O}+{\mathrm{O}}_2$

$2){\mathrm{H}}_2{\mathrm{O}}_2+\mathrm{HOCl}\to {\mathrm{Cl}}^{–}+{\mathrm{H}}_3{\mathrm{O}}^{+}+{\mathrm{O}}_2$

Fill in the missing data in the following table