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 preparation of baking soda,what is the ratio of $H_2O$ and $CO_2$ used to react with $Na_2CO_3$ to form $NaHCO_3$?

Calculate the weight of $CaO$ formed in quintals when $10 \ g$ of $CaCO_3$ is heated with $4.4 \ g$ of $CO_2$.

Aluminium reacts with sulfuric acid to form aluminium sulfate and hydrogen. What is the volume of hydrogen gas in liters $(L)$ produced at $300 \ K$ and $1.0 \ atm$ pressure,when $5.4 \ g$ of aluminium and $50.0 \ mL$ of $5.0 \ M$ sulfuric acid are combined for the reaction?
(Use molar mass of aluminium as $27.0 \ g \ mol^{-1}, R = 0.082 \ atm \ L \ mol^{-1} \ K^{-1}$)

$A$ closed $10 \, L$ vessel contains $1 \, L$ water gas $(1:1 \, CO : H_2)$ and $9 \, L$ air ($20 \% \, O_2$ by volume) at $STP$. The contents of the vessel are ignited. The number of moles of $CO_2$ in the vessel is closest to $.... \, mol$.

Calculate the amount of carbon dioxide produced when:
$(i)$ $1$ mole of carbon is burnt in air.
$(ii)$ $1$ mole of carbon is burnt in $16 \ g$ of dioxygen.
$(iii)$ $2$ moles of carbon are burnt in $16 \ g$ of dioxygen.