Q. The standard redox potentials for the reactions ${Mn}^{2 +} + {2e}^{-}\ \ \longrightarrow and\ {Mn}^{3 +} + \ e^{-}\ \longrightarrow \ M^{2 +}$ are -1.18 V and 1.51 V respectively. What is the redox potenital for the reaction ${Mn}^{3 +} + \ {3e}^{-}\ \longrightarrow Mn\ ?$
A) 0.33 V
B) 1.69 V
C) -0.28 V
D) - 0.85
Explanation
(c)
$E^{{^\circ}}$ n$E^{{^\circ}}$
${Mn}^{2 +} + \ {2e}^{-}\ \rightarrow Mn\ \ \ \ \ \ \$ -1.18 V -2.36 ${Mn}^{3 +}\ + \ e^{-}\ \rightarrow \ {Mn}^{2 +}\ \ \ \ \ \ \ \ \ \ \ 1.51\ V\ \ \ \ \ \ \ \ \ 1.51\ V$
${Mn}^{3 +}\ + \ {3e}^{-}\ \rightarrow \ Mn\ \ \ \ \ \ \ \ \ \ - 0.28\ \ \ \ \ \ \ - 0.85$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.