${\text{4Mg\hspace{0.17em}+\hspace{0.17em}10HNO}}_{\text{3}}\to \text{\hspace{0.17em}4mg}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}{\text{\hspace{0.17em}+\hspace{0.17em}NH}}_{\text{4}}{\text{NO}}_{\text{3}}{\text{\hspace{0.17em}+\hspace{0.17em}3H}}_{\text{2}}\text{O}$. In this reaction 

96 gms magnesium can reduce one mole of ${\text{HNO}}_{\text{3}}$

Equivalent weight of reduced ${\text{HNO}}_{\text{3}}$ is $\frac{1}{8}$th of its molecular weight

Entire ${\text{HNO}}_{\text{3}}$ involved in the reaction is reduced

${\text{HNO}}_{\text{3}}$ is reduced to the best possible extent