Chemistry - Redox Reactions Question with Solution | TestHub

${\mathrm{n}}_1{\mathrm{Cr}}_2{\mathrm{O}}_7^{-2}+{\mathrm{n}}_2{\mathrm{FeC}}_2{\mathrm{O}}_4\underset{\text{ Medium }}{\overset{\text{ Acidic }}{\to }}{\mathrm{n}}_3{\mathrm{Cr}}^{+3}+{\mathrm{n}}_4{\mathrm{Fe}}^{+3}+{\mathrm{n}}_5{\mathrm{CO}}_2+{\mathrm{n}}_6{\mathrm{H}}_2\mathrm{O}$ here ${\mathrm{n}}_1,{\mathrm{n}}_2,{\mathrm{n}}_3,{\mathrm{n}}_4,{\mathrm{n}}_5$ and ${\mathrm{n}}_6$ are simplest non fractional coefficients of the balanced redox reaction. Then value of $\left[{\mathrm{n}}_1+{\mathrm{n}}_2+{\mathrm{n}}_3+{\mathrm{n}}_4+{\mathrm{n}}_5+{\mathrm{n}}_6\right]$ is: