$1.0 \ g$ of pure calcium carbonate was found to require $50 \ mL$ of dilute $HCl$ for complete reaction. The strength of the $HCl$ solution is given by ........ $N$.

Heating oxygen in the presence of a catalyst results in $15\%$ conversion to ozone. How many grams of oxygen are required to produce $33.6 \ L$ of $O_3$ at $STP$?

Volume of $3 \ M \ NaOH$ (formula weight $40 \ g \ mol^{-1}$) which can be prepared from $84 \ g$ of $NaOH$ is $ . . . . . . \times 10^{-1} \ dm^3$.

$A$ mixture of dihydrogen and dioxygen at $1 \ bar$ pressure contains $20 \%$ by weight of dihydrogen. Calculate the partial pressure of dihydrogen. (in $bar$)

Match the following and select the correct option:

List-$I$	List-$II$ (At $STP$)
$(A)$ $10 \ g \ CaCO_3 \xrightarrow{\Delta} \text{decomposition}$	$(i)$ $0.224 \ L \ CO_2$
$(B)$ $1.06 \ g \ Na_2CO_3 \xrightarrow{\text{Excess } HCl}$	$(ii)$ $4.48 \ L \ CO_2$
$(C)$ $2.4 \ g \ C \xrightarrow{\text{Excess } O_2} \text{combustion}$	$(iii)$ $0.448 \ L \ CO_2$
$(D)$ $0.56 \ g \ CO \xrightarrow{\text{Excess } O_2} \text{combustion}$	$(iv)$ $2.24 \ L \ CO_2$
	$(v)$ $22.4 \ L \ CO_2$

$SO_{2}Cl_{2}$ on reaction with excess of water results in an acidic mixture: $SO_{2}Cl_{2} + 2H_{2}O \rightarrow H_{2}SO_{4} + 2HCl$. If $16 \, moles$ of $NaOH$ is required for the complete neutralization of the resultant acidic mixture,calculate the number of moles of $SO_{2}Cl_{2}$ used.