$\mathrm{NX}$ is produced by the following step of reactions:

$\mathrm{M}+{\mathrm{X}}_2⟶{\mathrm{MX}}_2$
$3{\mathrm{MX}}_2+{\mathrm{X}}_2⟶{\mathrm{M}}_3{\mathrm{X}}_8$
${\mathrm{M}}_3{\mathrm{X}}_8+{\mathrm{N}}_2{\mathrm{CO}}_3⟶\mathrm{NX}+{\mathrm{CO}}_2+{\mathrm{M}}_3{\mathrm{O}}_4$

How much $\mathrm{M}$ (metal) is consumed to produce $206 \mathrm{g}$ of $\mathrm{NX}$. (Take at $\mathrm{wt}$of $\mathrm{M}=56, \mathrm{N}=23, \mathrm{X}=80$)

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

$\mathrm{Nal}+{\mathrm{AgNO}}_3⟶\mathrm{Agl}+{\mathrm{NaNO}}_3$; 

$2\mathrm{Agl}+\mathrm{Fe}\to {\mathrm{Fel}}_2+2\mathrm{Ag}$

$2{\mathrm{Fel}}_2+3{\mathrm{Cl}}_2⟶2{\mathrm{FeCl}}_3+2{\mathrm{l}}_2$

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.

$500\mathrm{mL}$ of a glucose solution contains $6.02\times {10}^{22}$ molecules. The concentration of the solution is;