$200 \mathrm{mL}$ of any gas at $\mathrm{N}.\mathrm{T}.\mathrm{P}$ was heated with tin. Tin got converted into stannous sulphide and hydrogen was left. This hydrogen when passed over hot $\mathrm{CuO}$, produced $0.162 \mathrm{g}$ of ${\mathrm{H}}_2\mathrm{O}$. Suppose the vapour density of the gas is $17$, find its formula.

Calculate the amount of $\mathrm{Ni}$ needed in the Mond's process given below.

$\mathrm{Ni}+4\mathrm{CO}⟶\mathrm{Ni}(\mathrm{CO}{)}_4$

If $\mathrm{CO}$ used in this process is obtained through a process, in which $6 \mathrm{g}$ of carbon is mixed with $44 \mathrm{g} {\mathrm{CO}}_2$.

$\mathrm{NX}$ is produced by the following steps of reaction: 

$\mathrm{M}+{\mathrm{X}}_2⟶{\mathrm{MX}}_2$

$3{\mathrm{MX}}_2+{\mathrm{X}}_2⟶{\mathrm{M}}_3{\mathrm{X}}_8$

${\mathrm{M}}_3{\mathrm{X}}_8+{\mathrm{N}}_2{\mathrm{CO}}_3⟶\mathrm{NX}+{\mathrm{CO}}_2+{\mathrm{M}}_3{\mathrm{O}}_4$

How much $\mathrm{M}$ (metal) is consumed to produce $206 \mathrm{g}$ of $\mathrm{NX}$? $\left(\mathrm{Take} \mathrm{Atomic} \mathrm{weight} \mathrm{M}=56, \mathrm{N}=23, \mathrm{X}=80\right)$

The following process has been used to obtain iodine from oil-field brines in California.

$\mathrm{NaI}+{\mathrm{AgNO}}_3⟶\mathrm{AgI}+{\mathrm{NaNO}}_3$

$2\mathrm{AgI}+\mathrm{Fe}⟶{\mathrm{FeI}}_2+2\mathrm{Ag}$

$2{\mathrm{FeI}}_2+3{\mathrm{Cl}}_2⟶2{\mathrm{FeCl}}_3+2{\mathrm{I}}_2$

How many grams of ${\mathrm{AgNO}}_3$ are required in the first step for every $254 \mathrm{kg} {\mathrm{I}}_2$ produced in the third step? 

If $20.0 \mathrm{g}$ of ${\mathrm{CaCO}}_3$ is treated with $20.0 \mathrm{g}$ of $\mathrm{HCl}$, how many grams of ${\mathrm{CO}}_2$ can be produced according to the reaction: 

${\mathrm{CaCO}}_3\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)⟶{\mathrm{CaCl}}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)$

$\mathrm{A}+\mathrm{B}\to {\mathrm{A}}_3{\mathrm{B}}_2$ (unbalanced) 

${\mathrm{A}}_3{\mathrm{B}}_2+\mathrm{C}\to {\mathrm{A}}_3{\mathrm{B}}_2{\mathrm{C}}_2$ (unbalanced) 

Above two reactions are carried out by taking $3$ moles each of $\mathrm{A}$ and $\mathrm{B}$ and one mole of $\mathrm{C}$. Then which option is/are correct?