Question

Calculate the total n-factor for the reduction half reaction given below:
$F{e}_2(S{O}_4{)}_3⟶FeO+S{O}_2$

• A. 4
• B. 8
• C. 6
• D. 5

Answer 1

The correct option is B 8

For the given reaction :
$\stackrel{+3}{F}{e}_2\left(\stackrel{+6}{S}{O}_4{)}_3\right(s)⟶\stackrel{+2}{F}eO(s)+\stackrel{+4}{S}{O}_2(g)$
Reduction :
$F{e}^{+3}⟶F{e}^{+2}$
$n_f=|3-2|\times 2=2$
Reduction :
$S^{+6}⟶S^{+4}$
$n_f=|6-4|\times 3=6$
$(n_f{)}_T=(n_f{)}_{Fe}+(n_f{)}_S=2+6=8$