$8 \ L$ of $H_2$ and $6 \ L$ of $Cl_2$ react to the maximum extent. Find the final volume of the reaction mixture in $L$. Assume $P$ and $T$ remain constant throughout the process.

For the given reaction:
$CaCO_{3} + 2HCl \to CaCl_{2} + H_{2}O + CO_{2}$
If $90 \ g$ of $CaCO_{3}$ is added to $300 \ mL$ of $HCl$ solution which contains $38.55\%$ $HCl$ by mass and has a density of $1.13 \ g \ mL^{-1}$,then which of the following options is correct?
[Given molar masses of $H$,$Cl$,$Ca$,and $O$ are $1$,$35.5$,$40$,and $16 \ g \ mol^{-1}$ respectively]

In the balanced equation of the following reaction,the ratio of $a / b$ is: $aCaCO_3 + bH_3PO_4 \rightarrow pCa_3(PO_4)_2 + qCO_2 + rH_2O$

The maximum amount of $BaSO_4$ precipitated on mixing equal volumes of $BaCl_2$ $(0.5 \ M)$ with $H_2SO_4$ $(1 \ M)$ will correspond to ................. $M$.

On reaction of $38.1 \ g$ iodine and $28.4 \ g$ chlorine,a mixture of $ICl$ and $ICl_3$ is obtained. What will be the total number of moles after the reaction?

Production of iron in a blast furnace follows the following equation:
$Fe_{3}O_{4(s)} + 4CO_{(g)} \rightarrow 3Fe_{(s)} + 4CO_{2(g)}$
When $4.640 \ kg$ of $Fe_{3}O_{4}$ and $2.520 \ kg$ of $CO$ are allowed to react,the amount of iron (in $g$) produced is $....$
[Given: Molar Atomic mass $(g \ mol^{-1}): Fe = 56, O = 16, C = 12$]