If $5$ moles of $BaCl_2$ is mixed with $2$ moles of $Na_3PO_4$,the maximum number of moles of $Ba_3(PO_4)_2$ formed is $..........$ (Nearest integer)

In the Haber process,$30 \ L$ of dihydrogen and $30 \ L$ of dinitrogen were taken for the reaction,which yielded only $50\%$ of the expected product. What will be the composition of the gaseous mixture under the aforesaid condition in the end?

$100 \ g$ of propane is completely reacted with $1000 \ g$ of oxygen. The mole fraction of carbon dioxide in the resulting mixture is $x \times 10^{-2}$. The value of $x$ is ..... .
(Nearest integer)
[Atomic weight : $H=1.008$ ; $C=12.00$ ; $O=16.00$ ]

Phosphoric acid is prepared commercially from phosphate ore as follows:
$Ca_3(PO_4)_2 + 3SiO_2 + 5C + 5O_2 + 3H_2O \to 3CaSiO_3 + 5CO_2 + 2H_3PO_4$
If $1.0 \ kg$ each of calcium phosphate and silica are used with an excess of $C$,$O_2$,and $H_2O$,what is the maximum quantity of phosphoric acid that can be produced (in $kg$)? (Atomic masses: $Ca = 40, P = 31, Si = 28, O = 16, H = 1$)

For the reaction $A + 2B \rightarrow C$,$5 \ \text{mol}$ of $A$ and $8 \ \text{mol}$ of $B$ produce how many moles of $C$?

Balance the following chemical equations:
$(i)$ $Cu_2S + O_2 \to Cu_2O + SO_2$
$(ii)$ $Ca_3(PO_4)_2 + H_2SO_4 \to Ca(H_2PO_4)_2 + CaSO_4$