$A$ 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 $.... \, mol$.

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: $Ca = 40, P = 31, Si = 28, O = 16, H = 1$)

Consider the following reaction occurring in the blast furnace: $Fe_3O_{4(s)} + 4CO_{(g)} \rightarrow 3Fe_{(l)} + 4CO_{2(g)}$. '$x$' kg of iron is produced when $2.32 \times 10^3 \ kg$ of $Fe_3O_4$ and $2.8 \times 10^2 \ kg$ of $CO$ are brought together in the furnace. The value of '$x$' is $.............$ (nearest integer). Given: Molar mass of $Fe_3O_4 = 232 \ g \ mol^{-1}$,Molar mass of $CO = 28 \ g \ mol^{-1}$,Molar mass of $Fe = 56 \ g \ mol^{-1}$.

What are $x$ and $y$ in the following reaction?
$x Pb_3O_4 \rightarrow y PbO + O_2$

Calculate the maximum possible heat which can be released if a $4 \ L$ aqueous solution is to be formed by mixing appropriate volumes of $2 \ M$ $NaOH$ and $3 \ M$ $H_2SO_4$ solution. Given $\Delta H_{\text{neutralisation, SA/SB}} = -14 \ kcal/mol$.

$NH_3$ is produced according to the following reaction: $N_{2(g)} + 3H_{2(g)} \rightarrow 2NH_{3(g)}$. In an experiment,$0.25 \ mol$ of $NH_3$ is formed when $0.5 \ mol$ of $N_2$ is reacted with $0.5 \ mol$ of $H_2$. What is the percentage yield (in $\%$)?