How many moles of lead chloride will be produced by the reaction of $6.5 \ g$ of $PbO$ and $3.2 \ g$ of $HCl$?

Balance the following chemical equation by choosing the correct option for the coefficients $x, y, p, q, r,$ and $s$.
$x KNO_3 + y C_{12}H_{22}O_{11} \longrightarrow p N_2 + q CO_2 + r H_2O + s K_2CO_3$

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

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

$0.4 \text{ g}$ of dihydrogen is made to react with $7.4 \text{ g}$ of dichlorine to form hydrogen chloride. The volume of hydrogen chloride formed at $273 \text{ K}$ and $1 \text{ bar}$ pressure is: (in $\text{ L}$)

The mass of water produced when $4 \ g$ of hydrogen reacts with $4 \ g$ of oxygen is .......... $g$.