Question

Identify the reducing agent in the redox reaction

$5S{O}_3^{2-}+2Mn{O}_4^{-}+6H^{+}\to 5S{O}_4^{2-}+2M{n}^{2+}+3H_{2}O$

• A. $Mn$
• B. $S{O}_3^{2-}$
• C. both a and b
• D. None of the above

Answer 1

The correct option is B $S{O}_3^{2-}$

$\stackrel{+4}{5}S{O}_3^{2-}+2Mn{O}_4^{-}+6H^{+}⟶\stackrel{+6}{5}S{O}_4^{2-}+2M{n}^{+2}+3H_{2}O$

$\downarrow$ $⟶$ $\uparrow$

{Oxidation}

$\because S{O}_3^{2-}$ is undergoing increase in oxidation state i.e; oxidation so it is a reducing agent.