Question

Consider the following reactions:

(i) $C_{2}O_{4}^{2 -} \rightarrow CO_{2}$

(ii) $SO_{4}^{2 -} \rightarrow SO_{3}^{2 -}$

(iii) $MnO_{4}^{2 -} \rightarrow MnO_{4}^{-}$

(iv) $Fe^{3 +} \rightarrow Fe^{2 +}$

Choose the correct answer: -

• A. $\left(i\right) \, \& \, \left(\right.ii\left.\right)$ shows oxidation
• B. $\left(i i i\right) \, \& \, \left(i v\right)$ shows reduction
• C. $\left(i\right) \, \& \, \left(i i i\right)$ shows oxidation
• D. $\left(i i i\right) \, \& \, \left(i v\right)$ shows oxidation

Answer 1

Answer: (C)

In $C_{2}O_{4}^{2 -} \rightarrow CO_{2}$ oxidation number of carbon change from $+3$ $to \, +4$ .

In $SO_{4}^{2 -} \rightarrow SO_{3}^{2 -}$ oxidation number of sulphur change from $+6 \, to+4$ .

In $MnO_{4}^{2 -} \rightarrow MnO_{4}^{-}$ oxidation number of Mn change from $+6 \, to+7$ .

In $Fe^{3 +} \rightarrow Fe^{2 +}$ oxidation number of carbon change from +3 to +2.