Question

Find the n-factor of $F{e}_2{O}_3$ in the following chemical changes.
$F{e}_2{O}_3\to FeS{O}_4$

• A. 2
• B. 1
• C. 3
• D. \N

Answer 1

The correct option is A 2

Steps for finding valency factor/n-factor:
1. Find the oxidation state (O.S.) of metal in reactant side.
2. Find the oxidation state of metal in product side.
3. Take the magnitude of difference of two oxidation state $|O.S{.}_{Product}-O.S{.}_{Reactant}|\times \text{number of atom}$ for the valency factor
$F{e}_2{O}_3\to FeS{O}_4$
O.S. of Fe in reactant side
$=2x+3\times (-2)=0$
$x=+3$
O.S. of Fe in product side
$=x-2=0$
$x=+2$
$\text{valency factor}=\text{number of Fe atom}\times |O.S{.}_{Product}-O.S{.}_{Reactant}|$
$\text{valency factor}=2\times |+2-3|$
$\text{valency factor}=2$